Accessing nested JavaScript objects with string key

342

I have a data structure like this :

var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }, {

            'name': 'Part 3B',

            'size': '5',

            'qty' : '20'

        }, {

            'name': 'Part 3C',

            'size': '7.5',

            'qty' : '20'

        }

    ]

};

And I would like to access the data using these variable :

var part1name = "part1.name";

var part2quantity = "part2.qty";

var part3name1 = "part3[0].name";

part1name should be filled with someObject.part1.name 's value, which is "Part 1". Same thing with part2quantity which filled with 60.

Is there anyway to achieve this with either pure javascript or JQuery?

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

Not sure what you are asking here? You want to be able to query part1.name and have the text "part1.name" returned? Or you want a means to get the value stored within part1.name?

– BonyT
Jun 27 '11 at 10:27

have you tried doing like var part1name = someObject.part1name; `

– Rafay
Jun 27 '11 at 10:29

1

@BonyT : I want to query someObject.part1.name and return the value of it ("Part 1"). However, I want the query (I called it "the key") to be stored in a variable 'part1name'. Thanks for your reply. @3nigma : I have certainly do. But that is not my intention. Thanks for the reply.

– Komaruloh
Jun 27 '11 at 10:42

1

in the duplicate answer, i love fyr's answer stackoverflow.com/questions/8817394/…

– Steve Black
Mar 20 '13 at 2:09

1

See also Convert JavaScript string in dot notation into an object reference

– Bergi
Dec 15 '15 at 12:45

|
show 1 more comment

342

I have a data structure like this :

var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }, {

            'name': 'Part 3B',

            'size': '5',

            'qty' : '20'

        }, {

            'name': 'Part 3C',

            'size': '7.5',

            'qty' : '20'

        }

    ]

};

And I would like to access the data using these variable :

var part1name = "part1.name";

var part2quantity = "part2.qty";

var part3name1 = "part3[0].name";

part1name should be filled with someObject.part1.name 's value, which is "Part 1". Same thing with part2quantity which filled with 60.

Is there anyway to achieve this with either pure javascript or JQuery?

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

Not sure what you are asking here? You want to be able to query part1.name and have the text "part1.name" returned? Or you want a means to get the value stored within part1.name?

– BonyT
Jun 27 '11 at 10:27

have you tried doing like var part1name = someObject.part1name; `

– Rafay
Jun 27 '11 at 10:29

1

@BonyT : I want to query someObject.part1.name and return the value of it ("Part 1"). However, I want the query (I called it "the key") to be stored in a variable 'part1name'. Thanks for your reply. @3nigma : I have certainly do. But that is not my intention. Thanks for the reply.

– Komaruloh
Jun 27 '11 at 10:42

1

in the duplicate answer, i love fyr's answer stackoverflow.com/questions/8817394/…

– Steve Black
Mar 20 '13 at 2:09

1

See also Convert JavaScript string in dot notation into an object reference

– Bergi
Dec 15 '15 at 12:45

|
show 1 more comment

342

158

I have a data structure like this :

var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }, {

            'name': 'Part 3B',

            'size': '5',

            'qty' : '20'

        }, {

            'name': 'Part 3C',

            'size': '7.5',

            'qty' : '20'

        }

    ]

};

And I would like to access the data using these variable :

var part1name = "part1.name";

var part2quantity = "part2.qty";

var part3name1 = "part3[0].name";

part1name should be filled with someObject.part1.name 's value, which is "Part 1". Same thing with part2quantity which filled with 60.

Is there anyway to achieve this with either pure javascript or JQuery?

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

I have a data structure like this :

var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }, {

            'name': 'Part 3B',

            'size': '5',

            'qty' : '20'

        }, {

            'name': 'Part 3C',

            'size': '7.5',

            'qty' : '20'

        }

    ]

};

And I would like to access the data using these variable :

var part1name = "part1.name";

var part2quantity = "part2.qty";

var part3name1 = "part3[0].name";

part1name should be filled with someObject.part1.name 's value, which is "Part 1". Same thing with part2quantity which filled with 60.

Is there anyway to achieve this with either pure javascript or JQuery?

javascript jquery path nested

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

edited Aug 15 '17 at 16:57

Paul Roub

32.6k85773

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

asked Jun 27 '11 at 10:25

Komaruloh

1,8153107

Not sure what you are asking here? You want to be able to query part1.name and have the text "part1.name" returned? Or you want a means to get the value stored within part1.name?

– BonyT
Jun 27 '11 at 10:27

have you tried doing like var part1name = someObject.part1name; `

– Rafay
Jun 27 '11 at 10:29

1

@BonyT : I want to query someObject.part1.name and return the value of it ("Part 1"). However, I want the query (I called it "the key") to be stored in a variable 'part1name'. Thanks for your reply. @3nigma : I have certainly do. But that is not my intention. Thanks for the reply.

– Komaruloh
Jun 27 '11 at 10:42

1

in the duplicate answer, i love fyr's answer stackoverflow.com/questions/8817394/…

– Steve Black
Mar 20 '13 at 2:09

1

See also Convert JavaScript string in dot notation into an object reference

– Bergi
Dec 15 '15 at 12:45

|
show 1 more comment

Not sure what you are asking here? You want to be able to query part1.name and have the text "part1.name" returned? Or you want a means to get the value stored within part1.name?

– BonyT
Jun 27 '11 at 10:27

have you tried doing like var part1name = someObject.part1name; `

– Rafay
Jun 27 '11 at 10:29

1

@BonyT : I want to query someObject.part1.name and return the value of it ("Part 1"). However, I want the query (I called it "the key") to be stored in a variable 'part1name'. Thanks for your reply. @3nigma : I have certainly do. But that is not my intention. Thanks for the reply.

– Komaruloh
Jun 27 '11 at 10:42

1

in the duplicate answer, i love fyr's answer stackoverflow.com/questions/8817394/…

– Steve Black
Mar 20 '13 at 2:09

1

See also Convert JavaScript string in dot notation into an object reference

– Bergi
Dec 15 '15 at 12:45

Not sure what you are asking here? You want to be able to query part1.name and have the text "part1.name" returned? Or you want a means to get the value stored within part1.name?

– BonyT
Jun 27 '11 at 10:27

have you tried doing like var part1name = someObject.part1name; `

– Rafay
Jun 27 '11 at 10:29

@BonyT : I want to query someObject.part1.name and return the value of it ("Part 1"). However, I want the query (I called it "the key") to be stored in a variable 'part1name'. Thanks for your reply. @3nigma : I have certainly do. But that is not my intention. Thanks for the reply.

– Komaruloh
Jun 27 '11 at 10:42

in the duplicate answer, i love fyr's answer stackoverflow.com/questions/8817394/…

– Steve Black
Mar 20 '13 at 2:09

See also Convert JavaScript string in dot notation into an object reference

– Bergi
Dec 15 '15 at 12:45

|
show 1 more comment

29 Answers
29

active

oldest

votes

440

I just made this based on some similar code I already had, it appears to work:

Object.byString = function(o, s) {

    s = s.replace(/[(w+)]/g, '.$1'); // convert indexes to properties

    s = s.replace(/^./, '');           // strip a leading dot

    var a = s.split('.');

    for (var i = 0, n = a.length; i < n; ++i) {

        var k = a[i];

        if (k in o) {

            o = o[k];

        } else {

            return;

        }

    }

    return o;

}

Usage::

Object.byString(someObj, 'part3[0].name');

See a working demo at http://jsfiddle.net/alnitak/hEsys/

EDIT some have noticed that this code will throw an error if passed a string where the left-most indexes don't correspond to a correctly nested entry within the object. This is a valid concern, but IMHO best addressed with a try / catch block when calling, rather than having this function silently return undefined for an invalid index.

edited Oct 10 '16 at 13:40

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

14

This works beautifully. Please contribute this to the internet by wrapping it as a node package.

– t3dodson
Jan 13 '15 at 22:38

9

@t3dodson I just did: github.com/capaj/object-resolve-path just be aware that this doesn't play nice when your property name contains '' in itself. Regex will replace it with '.' and it doesn't work as expected

– Capaj
Jul 30 '15 at 21:57

7

great stuff; using the lodash library, one can also do: _.get(object, nestedPropertyString);

– ian
Aug 13 '15 at 12:49

13

This will probably get lost in the sea of comments, however it errors if you try and address a property that doesn't exist. So 'part3[0].name.iDontExist'. Adding a check to see if o is an object in the if in fixes the issue. (How you go about that is up-to you). See updated fiddle: jsfiddle.net/hEsys/418

– ste2425
Nov 17 '15 at 11:12

2

This is so gold. We have a config based application and this is kinda helpful! Thanks!

– Christian Esperar
Jun 22 '16 at 15:52

|
show 15 more comments

132

This is the solution I use:

function resolve(path, obj=self, separator='.') {

    var properties = Array.isArray(path) ? path : path.split(separator)

    return properties.reduce((prev, curr) => prev && prev[curr], obj)

}

Example usage:

// accessing property path on global scope

resolve("document.body.style.width")

// or

resolve("style.width", document.body)



// accessing array indexes

// (someObject has been defined in the question)

resolve("part3.0.size", someObject) // returns '10'



// accessing non-existent properties

// returns undefined when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})



// accessing properties with unusual keys by changing the separator

var obj = { object: { 'a.property.name.with.periods': 42 } }

resolve('object->a.property.name.with.periods', obj, '->') // returns 42



// accessing properties with unusual keys by passing a property name array

resolve(['object', 'a.property.name.with.periods'], obj) // returns 42

Limitations:

Can't use brackets () for array indices—though specifying array indices between the separator token (e.g., .) works fine as shown above.

edited Aug 15 '18 at 0:59

answered Mar 2 '14 at 16:06

speigg

1,420195

7

using reduce is an excellent solution (one can also use _.reduce() from the underscore or lodash library)

– Alp
May 22 '14 at 14:51

2

I think self is probably undefined here. Do you mean this?

– Platinum Azure
Jun 17 '14 at 3:37

2

No, self is defined. this would be incorrect.

– speigg
Jun 18 '14 at 16:03

6

@PlatinumAzure developer.mozilla.org/en-US/docs/Web/API/Window.self

– Rahil Wazir
Nov 7 '14 at 10:15

1

Here's my complement to set values by path: pastebin.com/jDp5sKT9

– mroach
Jan 2 '17 at 8:42

|
show 6 more comments

125

This is now supported by lodash using _.get(obj, property). See https://lodash.com/docs#get

Example from the docs:

var object = { 'a': [{ 'b': { 'c': 3 } }] };



_.get(object, 'a[0].b.c');

// → 3



_.get(object, ['a', '0', 'b', 'c']);

// → 3



_.get(object, 'a.b.c', 'default');

// → 'default'

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

5

This should be the only accepted answer, because this is the only one working for both dot and bracket syntax and It doesn't fail, when we have '' in the string of a key in the path.

– Capaj
Aug 4 '15 at 2:12

5

This. Plus, it supports _.set(...)

– Josh C.
Aug 22 '17 at 6:23

what happes if the objet is not found?

– DDave
Oct 31 '17 at 16:58

@DDave if the value passed as the object is undefined or not an object, _.get will show the same behavior as when no key is found in the provided object. eg _.get(null, "foo") -> undefined, _.get(null, "foo", "bar") -> "bar". However this behavior is not defined in the docs so subject to change.

– Ian Walker-Sperber
Nov 2 '17 at 0:40

1

@Capaj you kiddin'? And who doesn't want/can't use lodash?

– Andre Figueiredo
Feb 19 '18 at 21:21

add a comment |

You'd have to parse the string yourself:

function getProperty(obj, prop) {

    var parts = prop.split('.');



    if (Array.isArray(parts)) {

        var last = parts.pop(),

        l = parts.length,

        i = 1,

        current = parts[0];



        while((obj = obj[current]) && i < l) {

            current = parts[i];

            i++;

        }



        if(obj) {

            return obj[last];

        }

    } else {

        throw 'parts is not valid array';

    }

}

This required that you also define array indexes with dot notation:

var part3name1 = "part3.0.name";

It makes the parsing easier.

DEMO

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

@Felix Kling : Your solution does provide me with what I need. And I thank you alot for that. But Alnitak also provide different ways and seem to work either. Since I can only choose one answer, I will choose Alnitak answer. Not that his solution is better than you or something like that. Anyway, I really appreciate your solution and effort you gave.

– Komaruloh
Jun 27 '11 at 11:25

1

@Komaruloh: Oh I thought you can always up vote answers on your own question.... anyway I was more or less kidding, I don't need more reputation ;) Happy coding!

– Felix Kling
Jun 27 '11 at 11:50

1

@Felix Kling : You need at least 15 reputation to up vote. :) I believe you don't need more reputation with 69k+ . Thanks

– Komaruloh
Jun 27 '11 at 14:58

@Felix FWIW - converting from syntax to property syntax is pretty trivial.

– Alnitak
Jun 27 '11 at 16:19

4

If you change the while loop to while (l > 0 && (obj = obj[current]) && i < l) then this code works for strings without dots as well.

– Snea
Aug 17 '14 at 6:18

|
show 2 more comments

Works for arrays / arrays inside the object also.
Defensive against invalid values.

/**

 * Retrieve nested item from object/array

 * @param {Object|Array} obj

 * @param {String} path dot separated

 * @param {*} def default value ( if result undefined )

 * @returns {*}

 */

function path(obj, path, def){

    var i, len;



    for(i = 0,path = path.split('.'), len = path.length; i < len; i++){

        if(!obj || typeof obj !== 'object') return def;

        obj = obj[path[i]];

    }



    if(obj === undefined) return def;

    return obj;

}



//////////////////////////

//         TEST         //

//////////////////////////



var arr = [true, {'sp ace': true}, true]



var obj = {

  'sp ace': true,

  arr: arr,

  nested: {'dotted.str.ing': true},

  arr3: arr

}



shouldThrow(`path(obj, "arr.0")`);

shouldBeDefined(`path(obj, "arr[0]")`);

shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);

shouldBeTrue(`path(obj, "sp ace")`);

shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");

shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);

<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>

edited Mar 27 '16 at 10:47

Endless

12.2k65070

answered Apr 24 '13 at 11:24

TheZver

7462915

9

Thanks this is the best and most performant answer - jsfiddle.net/Jw8XB/1

– Dominic
Jul 31 '13 at 23:00

@Endless, I'd like to emphasize the path should separate the items with dots. Braces won't work. I.e. to access first item in array use "0.sp ace".

– TheZver
Mar 27 '16 at 11:32

add a comment |

ES6: Only one line in Vanila JS (it return null if don't find instead of giving error):

'path.string'.split('.').reduce((p,c)=>p&&p[c]||null, MyOBJ)

or exemple:

'a.b.c'.split('.').reduce((p,c)=>p&&p[c]||null, {a:{b:{c:1}}})

For a ready to use function that also recognizes false, 0 and negative number and accept default values as parameter:

const resolvePath = (object, path, defaultValue) => path

   .split('.')

   .reduce((o, p) => o ? o[p] : defaultValue, object)

Exemple to use:

resolvePath(window,'document.body') => <body>

resolvePath(window,'document.body.xyz') => undefined

resolvePath(window,'document.body.xyz', null) => null

resolvePath(window,'document.body.xyz', 1) => 1

Bonus:

To set a path (Requested by @rob-gordon) you can use:

const setPath = (object, path, value) => path

   .split('.')

   .reduce((o,p) => o[p] = path.split('.').pop() === p ? value : o[p] || {}, object)

Example:

let myVar = {}

setPath(myVar, 'a.b.c', 42) => 42

console.log(myVar) => {a: {b: {c: 42}}}

Access array with :

const resolvePath = (object, path, defaultValue) => path

   .split(/[.[]'"]/)

   .filter(p => p)

   .reduce((o, p) => o ? o[p] : defaultValue, object)

exemple

const myVar = {a:{b:[{c:1}]}}

resolvePath(myVar,'a.b[0].c') => 1

resolvePath(myVar,'a["b"]['0'].c') => 1

edited Sep 19 '17 at 19:05

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

1

I love this technique. This is really messy but I wanted to use this technique for assignment. let o = {a:{b:{c:1}}}; let str = 'a.b.c'; str.split('.').splice(0, str.split('.').length - 1).reduce((p,c)=>p&&p[c]||null, o)[str.split('.').slice(-1)] = "some new value";

– rob-gordon
Jun 28 '17 at 17:15

1

I like the idea of using reduce but your logic seems off for 0, undefined and null values. {a:{b:{c:0}}} returns null instead of 0. Perhaps explicitly checking for null or undefined will clear up these issues. (p,c)=>p === undefined || p === null ? undefined : p[c]

– SmujMaiku
Oct 15 '17 at 17:31

Hi @SmujMaiku, the "ready to use" function return correctly for '0', 'undefined' and 'null', I just tested on the console: resolvePath({a:{b:{c:0}}},'a.b.c',null) => 0; It check if the key exists instead of the value itself which avoid more than one check

– Adriano Spadoni
Oct 16 '17 at 9:18

here defaultValue did not work, using Reflect.has(o, k) ? ... (ES6 Reflect.has) worked though

– Andre Figueiredo
Feb 23 '18 at 12:31

add a comment |

using eval:

var part1name = eval("someObject.part1.name");

wrap to return undefined on error

function path(obj, path) {

    try {

        return eval("obj." + path);

    } catch(e) {

        return undefined;

    }

}

http://jsfiddle.net/shanimal/b3xTw/

Please use common sense and caution when wielding the power of eval. It's a bit like a light saber, if you turn it on there's a 90% chance you'll sever a limb. Its not for everybody.

edited Apr 24 '14 at 6:55

community wiki

5 revs, 2 users 91%
Shanimal

5

Whether or not eval is a good idea depends on where the property string data is coming from. I doubt you have any reason to be concerned for hackers breaking in via a static "var p='a.b.c';eval(p);" type call. It's a perfectly fine idea for that.

– James Wilkins
Aug 21 '14 at 22:39

add a comment |

You can manage to obtain value of a deep object member with dot notation without any external JavaScript library with the simple following trick:

new Function('_', 'return _.' + path)(obj);

In your case to obtain value of part1.name from someObject just do:

new Function('_', 'return _.part1.name')(someObject);

Here is a simple fiddle demo: https://jsfiddle.net/harishanchu/oq5esowf/

edited Feb 24 '16 at 11:43

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

2

function deep_value ( obj, path ) { return new Function( 'o', 'return o.' + path )( obj ); }

– ArcangelZith
Jul 29 '16 at 4:59

add a comment |

Here I offer more ways, which seem faster in many respects:

Option 1: Split string on . or [ or ] or ' or ", reverse it, skip empty items.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var parts = path.split(/[|]|.|'|"/g).reverse(), name; // (why reverse? because it's usually faster to pop off the end of an array)

    while (parts.length) { name=parts.pop(); if (name) origin=origin[name]; }

    return origin;

}

Option 2 (fastest of all, except eval): Low level character scan (no regex/split/etc, just a quick char scan).
Note: This one does not support quotes for indexes.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c = '', pc, i = 0, n = path.length, name = '';

    if (n) while (i<=n) ((c = path[i++]) == '.' || c == '[' || c == ']' || c == void 0) ? (name?(origin = origin[name], name = ''):(pc=='.'||pc=='['||pc==']'&&c==']'?i=n+2:void 0),pc=c) : name += c;

    if (i==n+2) throw "Invalid path: "+path;

    return origin;

} // (around 1,000,000+/- ops/sec)

Option 3: (new: option 2 expanded to support quotes - a bit slower, but still fast)

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c, pc, i = 0, n = path.length, name = '', q;

    while (i<=n)

        ((c = path[i++]) == '.' || c == '[' || c == ']' || c == "'" || c == '"' || c == void 0) ? (c==q&&path[i]==']'?q='':q?name+=c:name?(origin?origin=origin[name]:i=n+2,name='') : (pc=='['&&(c=='"'||c=="'")?q=c:pc=='.'||pc=='['||pc==']'&&c==']'||pc=='"'||pc=="'"?i=n+2:void 0), pc=c) : name += c;

    if (i==n+2 || name) throw "Invalid path: "+path;

    return origin;

}

JSPerf: http://jsperf.com/ways-to-dereference-a-delimited-property-string/3

"eval(...)" is still king though (performance wise that is). If you have property paths directly under your control, there shouldn't be any issues with using 'eval' (especially if speed is desired). If pulling property paths "over the wire" (on the line!? lol :P), then yes, use something else to be safe. Only an idiot would say to never use "eval" at all, as there ARE good reasons when to use it. Also, "It is used in Doug Crockford's JSON parser." If the input is safe, then no problems at all. Use the right tool for the right job, that's it.

edited May 23 '17 at 11:55

Community♦

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

add a comment |

This will probably never see the light of day... but here it is anyway.

Replace bracket syntax with .

Split on . character

Remove blank strings

Find the path (otherwise undefined)

// "one liner" (ES6)



const deep_value = (obj, path) => 

  path

    .replace(/[|].?/g, '.')

    .split('.')

    .filter(s => s)

    .reduce((acc, val) => acc && acc[val], obj);

    

// ... and that's it.



var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }

        // ...

    ]

};



console.log(deep_value(someObject, "part1.name"));               // Part 1

console.log(deep_value(someObject, "part2.qty"));                // 60

console.log(deep_value(someObject, "part3[0].name"));            // Part 3A

edited Nov 10 '18 at 13:24

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

1

It did see the light of the day!! thanks

– abann sunny
Jan 15 at 21:01

add a comment |

I think you are asking for this:

var part1name = someObject.part1.name;

var part2quantity = someObject.part2.qty;

var part3name1 =  someObject.part3[0].name;

You could be asking for this:

var part1name = someObject["part1"]["name"];

var part2quantity = someObject["part2"]["qty"];

var part3name1 =  someObject["part3"][0]["name"];

Both of which will work

Or maybe you are asking for this

var partName = "part1";

var nameStr = "name";



var part1name = someObject[partName][nameStr];

Finally you could be asking for this

var partName = "part1.name";



var partBits = partName.split(".");



var part1name = someObject[partBits[0]][partBits[1]];

edited Jun 27 '11 at 20:46

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

I think OP's asking for the last solution. However, strings don't have Split method, but rather split.

– duri
Jun 27 '11 at 10:37

Actualy I was asking the last one. The partName variable is filled with string indicating the key-structure to value. Your solution seems makes sense. However I may need to modify for extended depth in the data, like 4-5 level and more. And I am wondering if I can treat the array and object uniformly with this?

– Komaruloh
Jun 27 '11 at 10:38

add a comment |

Speigg's approach is very neat and clean, though I found this reply while searching for the solution of accessing AngularJS $scope properties by string path and with a little modification it does the job:

$scope.resolve = function( path, obj ) {

    return path.split('.').reduce( function( prev, curr ) {

        return prev[curr];

    }, obj || this );

}

Just place this function in your root controller and use it any child scope like this:

$scope.resolve( 'path.to.any.object.in.scope')

answered Feb 26 '15 at 12:22

nesinervink

12818

add a comment |

It's a one liner with lodash.

const deep = { l1: { l2: { l3: "Hello" } } };

const prop = "l1.l2.l3";

const val = _.reduce(prop.split('.'), function(result, value) { return result ? result[value] : undefined; }, deep);

// val === "Hello"

Or even better...

const val = _.get(deep, prop);

Or ES6 version w/ reduce...

const val = prop.split('.').reduce((r, val) => { return r ? r[val] : undefined; }, deep);

Plunkr

edited Nov 18 '17 at 0:50

answered Dec 8 '16 at 16:19

James

2,4711615

add a comment |

I haven't yet found a package to do all of the operations with a string path, so I ended up writing my own quick little package which supports insert(), get() (with default return), set() and remove() operations.

You can use dot notation, brackets, number indices, string number properties, and keys with non-word characters. Simple usage below:

> var jsocrud = require('jsocrud');



...



// Get (Read) ---

> var obj = {

>     foo: [

>         {

>             'key w/ non-word chars': 'bar'

>         }

>     ]

> };

undefined



> jsocrud.get(obj, '.foo[0]["key w/ non-word chars"]');

'bar'

https://www.npmjs.com/package/jsocrud

https://github.com/vertical-knowledge/jsocrud

edited Apr 25 '15 at 1:32

answered Apr 25 '15 at 1:08

Kyle

314

add a comment |

Simple function, allowing for either a string or array path.

function get(obj, path) {

  if(typeof path === 'string') path = path.split('.');



  if(path.length === 0) return obj;

  return get(obj[path[0]], path.slice(1));

}



const obj = {a: {b: {c: 'foo'}}};



console.log(get(obj, 'a.b.c')); //foo

console.log(get(obj, ['a', 'b', 'c'])); //foo

edited Dec 26 '16 at 14:42

answered Dec 26 '16 at 4:51

Ben

1,4171317

If you're going to post code as an answer, please explain why the code answers the question.

– Tieson T.
Dec 26 '16 at 5:44

add a comment |

Just in case, anyone's visiting this question in 2017 or later and looking for an easy-to-remember way, here's an elaborate blog post on Accessing Nested Objects in JavaScript without being bamboozled by

Cannot read property 'foo' of undefined error

Access Nested Objects Using Array Reduce

Let's take this example structure

const user = {

    id: 101,

    email: 'jack@dev.com',

    personalInfo: {

        name: 'Jack',

        address: [{

            line1: 'westwish st',

            line2: 'washmasher',

            city: 'wallas',

            state: 'WX'

        }]

    }

}

To be able to access nested arrays, you can write your own array reduce util.

const getNestedObject = (nestedObj, pathArr) => {

    return pathArr.reduce((obj, key) =>

        (obj && obj[key] !== 'undefined') ? obj[key] : undefined, nestedObj);

}



// pass in your object structure as array elements

const name = getNestedObject(user, ['personalInfo', 'name']);



// to access nested array, just pass in array index as an element the path array.

const city = getNestedObject(user, ['personalInfo', 'address', 0, 'city']);

// this will return the city from the first address item.

There is also an excellent type handling minimal library typy that does all this for you.

With typy, your code will look like this

const city = t(user, 'personalInfo.address[0].city').safeObject;

Disclaimer: I am the author of this package.

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

add a comment |

There is an npm module now for doing this: https://github.com/erictrinh/safe-access

Example usage:

var access = require('safe-access');

access(very, 'nested.property.and.array[0]');

answered Jun 13 '14 at 18:56

caleb

1,3751420

add a comment |

/**

 * Access a deep value inside a object 

 * Works by passing a path like "foo.bar", also works with nested arrays like "foo[0][1].baz"

 * @author Victor B. https://gist.github.com/victornpb/4c7882c1b9d36292308e

 * Unit tests: http://jsfiddle.net/Victornpb/0u1qygrh/

 */

function getDeepVal(obj, path) {

    if (typeof obj === "undefined" || obj === null) return;

    path = path.split(/[.[]"']{1,2}/);

    for (var i = 0, l = path.length; i < l; i++) {

        if (path[i] === "") continue;

        obj = obj[path[i]];

        if (typeof obj === "undefined" || obj === null) return;

    }

    return obj;

}

Works with

getDeepVal(obj,'foo.bar')

getDeepVal(obj,'foo.1.bar')

getDeepVal(obj,'foo[0].baz')

getDeepVal(obj,'foo[1][2]')

getDeepVal(obj,"foo['bar'].baz")

getDeepVal(obj,"foo['bar']['baz']")

getDeepVal(obj,"foo.bar.0.baz[1]['2']['w'].aaa["f"].bb")

edited Sep 29 '16 at 19:51

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

add a comment |

While reduce is good, I am surprised no one used forEach:

function valueForKeyPath(obj, path){

        const keys = path.split('.');

        keys.forEach((key)=> obj = obj[key]);

        return obj;

    };

Test

edited Dec 15 '17 at 14:03

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

You are not even checking if obj[key] actually exists. It's unreliable.

– Carles Alcolea
Jul 22 '18 at 4:08

@CarlesAlcolea by default js will neither check if the key of an object exists: a.b.c will raise an exception if there is no property b in your object. If you need something silently dismissing the wrong keypath (which I do not recommend), you can still replace the forEach with this one keys.forEach((key)=> obj = (obj||{})[key]);

– Flavien Volken
Jul 23 '18 at 7:57

I run through it an object that was missing a curly brace, my bad :)

– Carles Alcolea
Jul 28 '18 at 23:59

add a comment |

If you need to access different nested key without knowing it at coding time (it will be trivial to address them) you can use the array notation accessor:

var part1name = someObject['part1']['name'];

var part2quantity = someObject['part2']['qty'];

var part3name1 =  someObject['part3'][0]['name'];

They are equivalent to the dot notation accessor and may vary at runtime, for example:

var part = 'part1';

var property = 'name';



var part1name = someObject[part][property];

is equivalent to

var part1name = someObject['part1']['name'];

var part1name = someObject.part1.name;

I hope this address your question...

EDIT

I won't use a string to mantain a sort of xpath query to access an object value.
As you have to call a function to parse the query and retrieve the value I would follow another path (not :

var part1name = function(){ return this.part1.name; }

var part2quantity = function() { return this['part2']['qty']; }

var part3name1 =  function() { return this.part3[0]['name'];}



// usage: part1name.apply(someObject);

or, if you are uneasy with the apply method

var part1name = function(obj){ return obj.part1.name; }

var part2quantity = function(obj) { return obj['part2']['qty']; }

var part3name1 =  function(obj) { return obj.part3[0]['name'];}



// usage: part1name(someObject);

The functions are shorter, clearer, the interpreter check them for you for syntax errors and so on.

By the way, I feel that a simple assignment made at right time will be sufficent...

edited Jun 27 '11 at 11:35

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

Interesting. But in my case, the someObject is initialize yet when I assign value to part1name. I only know the structure. That is why I use string to describe the structure. And hoping to be able to use it to query my data from someObject. Thanks for sharing your thought. :)

– Komaruloh
Jun 27 '11 at 10:47

@Komaruloh : I think you would write that the object is NOT initialized yet when you create your variables. By the way I don't get the point, why can't you do the assignment at appropriate time?

– Eineki
Jun 27 '11 at 11:24

Sorry about not mentioning that someObject is not initialized yet. As for the reason, someObject is fetch via web service. And I want to have an array of header which consist of part1name, part2qty, etc. So that I could just loop through the header array and get the value I wanted based on part1name value as the 'key'/path to someObject.

– Komaruloh
Jun 27 '11 at 11:47

add a comment |

Just had the same question recently and successfully used https://npmjs.org/package/tea-properties which also set nested object/arrays :

get:

var o = {

  prop: {

    arr: [

      {foo: 'bar'}

    ]

  }

};



var properties = require('tea-properties');

var value = properties.get(o, 'prop.arr[0].foo');



assert(value, 'bar'); // true

set:

var o = {};



var properties = require('tea-properties');

properties.set(o, 'prop.arr[0].foo', 'bar');



assert(o.prop.arr[0].foo, 'bar'); // true

edited Nov 4 '13 at 0:41

answered Oct 25 '13 at 19:33

abernier

13.2k156693

"This module has been discontinued. Use chaijs/pathval."

– Patrick Fisher
Mar 18 '14 at 0:09

add a comment |

The solutions here are just for accessing the deeply nested keys. I needed one for accessing, adding, modifying and deleting the keys. This is what I came up with:

var deepAccessObject = function(object, path_to_key, type_of_function, value){

    switch(type_of_function){

        //Add key/modify key

        case 0: 

            if(path_to_key.length === 1){

                if(value)

                    object[path_to_key[0]] = value;

                return object[path_to_key[0]];

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    object[path_to_key[0]] = {};

            }

            break;

        //delete key

        case 1:

            if(path_to_key.length === 1){

                delete object[path_to_key[0]];

                return true;

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    return false;

            }

            break;

        default:

            console.log("Wrong type of function");

    }

};

path_to_key: path in an array. You can replace it by your string_path.split(".").

type_of_function: 0 for accessing(dont pass any value to value), 0 for add and modify. 1 for delete.

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

add a comment |

Instead of a string an array can be used adressing nested objects and arrays e.g.: ["my_field", "another_field", 0, "last_field", 10]

Here is an example that would change a field based on this array representation. I am using something like that in react.js for controlled input fields that change the state of nested structures.

let state = {

        test: "test_value",

        nested: {

            level1: "level1 value"

        },

        arr: [1, 2, 3],

        nested_arr: {

            arr: ["buh", "bah", "foo"]

        }

    }



function handleChange(value, fields) {

    let update_field = state;

    for(var i = 0; i < fields.length - 1; i++){

        update_field = update_field[fields[i]];

    }

    update_field[fields[fields.length-1]] = value;

}



handleChange("update", ["test"]);

handleChange("update_nested", ["nested","level1"]);

handleChange(100, ["arr",0]);

handleChange('changed_foo', ["nested_arr", "arr", 3]);

console.log(state);

answered Oct 25 '17 at 8:12

Jodo

1,42611431

add a comment |

Based on a previous answer, I have created a function that can also handle brackets. But no dots inside them due to the split.

function get(obj, str) {

  return str.split(/.|[/g).map(function(crumb) {

    return crumb.replace(/]$/, '').trim().replace(/^(["'])((?:(?!1)[^\]|\.)*?)1$/, (match, quote, str) => str.replace(/\(\)?/g, "$1"));

  }).reduce(function(obj, prop) {

    return obj ? obj[prop] : undefined;

  }, obj);

}

answered Nov 1 '17 at 12:44

Vincent

1,3571018

add a comment |

// (IE9+) Two steps



var pathString = "[0]['property'].others[3].next['final']";

var obj = [{

  property: {

    others: [1, 2, 3, {

      next: {

        final: "SUCCESS"

      }

    }]

  }

}];



// Turn string to path array

var pathArray = pathString

    .replace(/[["']?([w]+)["']?]/g,".$1")

    .split(".")

    .splice(1);



// Add object prototype method

Object.prototype.path = function (path) {

  try {

    return [this].concat(path).reduce(function (f, l) {

      return f[l];

    });

  } catch (e) {

    console.error(e);

  }

};



// usage

console.log(obj.path(pathArray));

console.log(obj.path([0,"doesNotExist"]));

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

add a comment |

Working with `Underscore`'s `property` or `propertyOf`:

var test = {

  foo: {

    bar: {

      baz: 'hello'

    }

  }

}

var string = 'foo.bar.baz';





// document.write(_.propertyOf(test)(string.split('.')))



document.write(_.property(string.split('.'))(test));

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>

Good Luck...

answered Jun 22 '18 at 11:49

Akash

6,32013840

add a comment |

Inspired by @webjay's answer:
https://stackoverflow.com/a/46008856/4110122

I made this function which can you use it to Get/ Set/ Unset any value in object

function Object_Manager(obj, Path, value, Action) 

{

    try

    {

        if(Array.isArray(Path) == false)

        {

            Path = [Path];

        }



        let level = 0;

        var Return_Value;

        Path.reduce((a, b)=>{

            level++;

            if (level === Path.length)

            {

                if(Action === 'Set')

                {

                    a[b] = value;

                    return value;

                }

                else if(Action === 'Get')

                {

                    Return_Value = a[b];

                }

                else if(Action === 'Unset')

                {

                    delete a[b];

                }

            } 

            else 

            {

                return a[b];

            }

        }, obj);

        return Return_Value;

    }



    catch(err)

    {

        console.error(err);

        return obj;

    }

}

To use it:

 // Set

 Object_Manager(Obj,[Level1,Level2,Level3],New_Value, 'Set');



 // Get

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Get');



 // Unset

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Unset');

edited Nov 29 '18 at 8:15

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

add a comment |

-1

What about this solution:

setJsonValue: function (json, field, val) {

  if (field !== undefined){

    try {

      eval("json." + field + " = val");

    }

    catch(e){

      ;

    }

  }  

}

And this one, for getting:

getJsonValue: function (json, field){

  var value = undefined;

  if (field !== undefined) {

    try {

      eval("value = json." + field);

    } 

    catch(e){

      ;

    }

  }

  return value;

};

Probably some will consider them unsafe, but they must be much faster then, parsing the string.

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

add a comment |

-1

Building off of Alnitak's answer:

if(!Object.prototype.byString){

  //NEW byString which can update values

Object.prototype.byString = function(s, v, o) {

  var _o = o || this;

      s = s.replace(/[(w+)]/g, '.$1'); // CONVERT INDEXES TO PROPERTIES

      s = s.replace(/^./, ''); // STRIP A LEADING DOT

      var a = s.split('.'); //ARRAY OF STRINGS SPLIT BY '.'

      for (var i = 0; i < a.length; ++i) {//LOOP OVER ARRAY OF STRINGS

          var k = a[i];

          if (k in _o) {//LOOP THROUGH OBJECT KEYS

              if(_o.hasOwnProperty(k)){//USE ONLY KEYS WE CREATED

                if(v !== undefined){//IF WE HAVE A NEW VALUE PARAM

                  if(i === a.length -1){//IF IT'S THE LAST IN THE ARRAY

                    _o[k] = v;

                  }

                }

                _o = _o[k];//NO NEW VALUE SO JUST RETURN THE CURRENT VALUE

              }

          } else {

              return;

          }

      }

      return _o;

  };

}

This allows you to set a value as well!

I've created an npm package and github with this as well

edited Aug 15 '17 at 21:40

answered Aug 2 '17 at 19:16

Tamb

16919

add a comment |

protected by Samuel Liew♦ Oct 5 '15 at 9:21

Thank you for your interest in this question.
Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).

Would you like to answer one of these unanswered questions instead?

29 Answers
29

active

oldest

votes

29 Answers
29

active

oldest

votes

440

I just made this based on some similar code I already had, it appears to work:

Object.byString = function(o, s) {

    s = s.replace(/[(w+)]/g, '.$1'); // convert indexes to properties

    s = s.replace(/^./, '');           // strip a leading dot

    var a = s.split('.');

    for (var i = 0, n = a.length; i < n; ++i) {

        var k = a[i];

        if (k in o) {

            o = o[k];

        } else {

            return;

        }

    }

    return o;

}

Usage::

Object.byString(someObj, 'part3[0].name');

See a working demo at http://jsfiddle.net/alnitak/hEsys/

edited Oct 10 '16 at 13:40

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

14

This works beautifully. Please contribute this to the internet by wrapping it as a node package.

– t3dodson
Jan 13 '15 at 22:38

9

@t3dodson I just did: github.com/capaj/object-resolve-path just be aware that this doesn't play nice when your property name contains '' in itself. Regex will replace it with '.' and it doesn't work as expected

– Capaj
Jul 30 '15 at 21:57

7

great stuff; using the lodash library, one can also do: _.get(object, nestedPropertyString);

– ian
Aug 13 '15 at 12:49

13

This will probably get lost in the sea of comments, however it errors if you try and address a property that doesn't exist. So 'part3[0].name.iDontExist'. Adding a check to see if o is an object in the if in fixes the issue. (How you go about that is up-to you). See updated fiddle: jsfiddle.net/hEsys/418

– ste2425
Nov 17 '15 at 11:12

2

This is so gold. We have a config based application and this is kinda helpful! Thanks!

– Christian Esperar
Jun 22 '16 at 15:52

|
show 15 more comments

440

I just made this based on some similar code I already had, it appears to work:

Object.byString = function(o, s) {

    s = s.replace(/[(w+)]/g, '.$1'); // convert indexes to properties

    s = s.replace(/^./, '');           // strip a leading dot

    var a = s.split('.');

    for (var i = 0, n = a.length; i < n; ++i) {

        var k = a[i];

        if (k in o) {

            o = o[k];

        } else {

            return;

        }

    }

    return o;

}

Usage::

Object.byString(someObj, 'part3[0].name');

See a working demo at http://jsfiddle.net/alnitak/hEsys/

edited Oct 10 '16 at 13:40

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

14

This works beautifully. Please contribute this to the internet by wrapping it as a node package.

– t3dodson
Jan 13 '15 at 22:38

9

@t3dodson I just did: github.com/capaj/object-resolve-path just be aware that this doesn't play nice when your property name contains '' in itself. Regex will replace it with '.' and it doesn't work as expected

– Capaj
Jul 30 '15 at 21:57

7

great stuff; using the lodash library, one can also do: _.get(object, nestedPropertyString);

– ian
Aug 13 '15 at 12:49

13

This will probably get lost in the sea of comments, however it errors if you try and address a property that doesn't exist. So 'part3[0].name.iDontExist'. Adding a check to see if o is an object in the if in fixes the issue. (How you go about that is up-to you). See updated fiddle: jsfiddle.net/hEsys/418

– ste2425
Nov 17 '15 at 11:12

2

This is so gold. We have a config based application and this is kinda helpful! Thanks!

– Christian Esperar
Jun 22 '16 at 15:52

|
show 15 more comments

440

I just made this based on some similar code I already had, it appears to work:

Object.byString = function(o, s) {

    s = s.replace(/[(w+)]/g, '.$1'); // convert indexes to properties

    s = s.replace(/^./, '');           // strip a leading dot

    var a = s.split('.');

    for (var i = 0, n = a.length; i < n; ++i) {

        var k = a[i];

        if (k in o) {

            o = o[k];

        } else {

            return;

        }

    }

    return o;

}

Usage::

Object.byString(someObj, 'part3[0].name');

See a working demo at http://jsfiddle.net/alnitak/hEsys/

edited Oct 10 '16 at 13:40

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

I just made this based on some similar code I already had, it appears to work:

Object.byString = function(o, s) {

    s = s.replace(/[(w+)]/g, '.$1'); // convert indexes to properties

    s = s.replace(/^./, '');           // strip a leading dot

    var a = s.split('.');

    for (var i = 0, n = a.length; i < n; ++i) {

        var k = a[i];

        if (k in o) {

            o = o[k];

        } else {

            return;

        }

    }

    return o;

}

Usage::

Object.byString(someObj, 'part3[0].name');

See a working demo at http://jsfiddle.net/alnitak/hEsys/

edited Oct 10 '16 at 13:40

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

edited Oct 10 '16 at 13:40

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

answered Jun 27 '11 at 10:40

Alnitak

270k62341432

14

This works beautifully. Please contribute this to the internet by wrapping it as a node package.

– t3dodson
Jan 13 '15 at 22:38

9

@t3dodson I just did: github.com/capaj/object-resolve-path just be aware that this doesn't play nice when your property name contains '' in itself. Regex will replace it with '.' and it doesn't work as expected

– Capaj
Jul 30 '15 at 21:57

7

great stuff; using the lodash library, one can also do: _.get(object, nestedPropertyString);

– ian
Aug 13 '15 at 12:49

13

This will probably get lost in the sea of comments, however it errors if you try and address a property that doesn't exist. So 'part3[0].name.iDontExist'. Adding a check to see if o is an object in the if in fixes the issue. (How you go about that is up-to you). See updated fiddle: jsfiddle.net/hEsys/418

– ste2425
Nov 17 '15 at 11:12

2

This is so gold. We have a config based application and this is kinda helpful! Thanks!

– Christian Esperar
Jun 22 '16 at 15:52

|
show 15 more comments

14

This works beautifully. Please contribute this to the internet by wrapping it as a node package.

– t3dodson
Jan 13 '15 at 22:38

9

@t3dodson I just did: github.com/capaj/object-resolve-path just be aware that this doesn't play nice when your property name contains '' in itself. Regex will replace it with '.' and it doesn't work as expected

– Capaj
Jul 30 '15 at 21:57

7

great stuff; using the lodash library, one can also do: _.get(object, nestedPropertyString);

– ian
Aug 13 '15 at 12:49

13

This will probably get lost in the sea of comments, however it errors if you try and address a property that doesn't exist. So 'part3[0].name.iDontExist'. Adding a check to see if o is an object in the if in fixes the issue. (How you go about that is up-to you). See updated fiddle: jsfiddle.net/hEsys/418

– ste2425
Nov 17 '15 at 11:12

2

This is so gold. We have a config based application and this is kinda helpful! Thanks!

– Christian Esperar
Jun 22 '16 at 15:52

This works beautifully. Please contribute this to the internet by wrapping it as a node package.

– t3dodson
Jan 13 '15 at 22:38

@t3dodson I just did: github.com/capaj/object-resolve-path just be aware that this doesn't play nice when your property name contains '' in itself. Regex will replace it with '.' and it doesn't work as expected

– Capaj
Jul 30 '15 at 21:57

great stuff; using the lodash library, one can also do: _.get(object, nestedPropertyString);

– ian
Aug 13 '15 at 12:49

This will probably get lost in the sea of comments, however it errors if you try and address a property that doesn't exist. So 'part3[0].name.iDontExist'. Adding a check to see if o is an object in the if in fixes the issue. (How you go about that is up-to you). See updated fiddle: jsfiddle.net/hEsys/418

– ste2425
Nov 17 '15 at 11:12

This is so gold. We have a config based application and this is kinda helpful! Thanks!

– Christian Esperar
Jun 22 '16 at 15:52

|
show 15 more comments

132

This is the solution I use:

function resolve(path, obj=self, separator='.') {

    var properties = Array.isArray(path) ? path : path.split(separator)

    return properties.reduce((prev, curr) => prev && prev[curr], obj)

}

Example usage:

// accessing property path on global scope

resolve("document.body.style.width")

// or

resolve("style.width", document.body)



// accessing array indexes

// (someObject has been defined in the question)

resolve("part3.0.size", someObject) // returns '10'



// accessing non-existent properties

// returns undefined when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})



// accessing properties with unusual keys by changing the separator

var obj = { object: { 'a.property.name.with.periods': 42 } }

resolve('object->a.property.name.with.periods', obj, '->') // returns 42



// accessing properties with unusual keys by passing a property name array

resolve(['object', 'a.property.name.with.periods'], obj) // returns 42

Limitations:

Can't use brackets () for array indices—though specifying array indices between the separator token (e.g., .) works fine as shown above.

edited Aug 15 '18 at 0:59

answered Mar 2 '14 at 16:06

speigg

1,420195

7

using reduce is an excellent solution (one can also use _.reduce() from the underscore or lodash library)

– Alp
May 22 '14 at 14:51

2

I think self is probably undefined here. Do you mean this?

– Platinum Azure
Jun 17 '14 at 3:37

2

No, self is defined. this would be incorrect.

– speigg
Jun 18 '14 at 16:03

6

@PlatinumAzure developer.mozilla.org/en-US/docs/Web/API/Window.self

– Rahil Wazir
Nov 7 '14 at 10:15

1

Here's my complement to set values by path: pastebin.com/jDp5sKT9

– mroach
Jan 2 '17 at 8:42

|
show 6 more comments

132

This is the solution I use:

function resolve(path, obj=self, separator='.') {

    var properties = Array.isArray(path) ? path : path.split(separator)

    return properties.reduce((prev, curr) => prev && prev[curr], obj)

}

Example usage:

// accessing property path on global scope

resolve("document.body.style.width")

// or

resolve("style.width", document.body)



// accessing array indexes

// (someObject has been defined in the question)

resolve("part3.0.size", someObject) // returns '10'



// accessing non-existent properties

// returns undefined when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})



// accessing properties with unusual keys by changing the separator

var obj = { object: { 'a.property.name.with.periods': 42 } }

resolve('object->a.property.name.with.periods', obj, '->') // returns 42



// accessing properties with unusual keys by passing a property name array

resolve(['object', 'a.property.name.with.periods'], obj) // returns 42

Limitations:

Can't use brackets () for array indices—though specifying array indices between the separator token (e.g., .) works fine as shown above.

edited Aug 15 '18 at 0:59

answered Mar 2 '14 at 16:06

speigg

1,420195

7

using reduce is an excellent solution (one can also use _.reduce() from the underscore or lodash library)

– Alp
May 22 '14 at 14:51

2

I think self is probably undefined here. Do you mean this?

– Platinum Azure
Jun 17 '14 at 3:37

2

No, self is defined. this would be incorrect.

– speigg
Jun 18 '14 at 16:03

6

@PlatinumAzure developer.mozilla.org/en-US/docs/Web/API/Window.self

– Rahil Wazir
Nov 7 '14 at 10:15

1

Here's my complement to set values by path: pastebin.com/jDp5sKT9

– mroach
Jan 2 '17 at 8:42

|
show 6 more comments

132

This is the solution I use:

function resolve(path, obj=self, separator='.') {

    var properties = Array.isArray(path) ? path : path.split(separator)

    return properties.reduce((prev, curr) => prev && prev[curr], obj)

}

Example usage:

// accessing property path on global scope

resolve("document.body.style.width")

// or

resolve("style.width", document.body)



// accessing array indexes

// (someObject has been defined in the question)

resolve("part3.0.size", someObject) // returns '10'



// accessing non-existent properties

// returns undefined when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})



// accessing properties with unusual keys by changing the separator

var obj = { object: { 'a.property.name.with.periods': 42 } }

resolve('object->a.property.name.with.periods', obj, '->') // returns 42



// accessing properties with unusual keys by passing a property name array

resolve(['object', 'a.property.name.with.periods'], obj) // returns 42

Limitations:

Can't use brackets () for array indices—though specifying array indices between the separator token (e.g., .) works fine as shown above.

edited Aug 15 '18 at 0:59

answered Mar 2 '14 at 16:06

speigg

1,420195

This is the solution I use:

function resolve(path, obj=self, separator='.') {

    var properties = Array.isArray(path) ? path : path.split(separator)

    return properties.reduce((prev, curr) => prev && prev[curr], obj)

}

Example usage:

// accessing property path on global scope

resolve("document.body.style.width")

// or

resolve("style.width", document.body)



// accessing array indexes

// (someObject has been defined in the question)

resolve("part3.0.size", someObject) // returns '10'



// accessing non-existent properties

// returns undefined when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})



// accessing properties with unusual keys by changing the separator

var obj = { object: { 'a.property.name.with.periods': 42 } }

resolve('object->a.property.name.with.periods', obj, '->') // returns 42



// accessing properties with unusual keys by passing a property name array

resolve(['object', 'a.property.name.with.periods'], obj) // returns 42

Limitations:

Can't use brackets () for array indices—though specifying array indices between the separator token (e.g., .) works fine as shown above.

edited Aug 15 '18 at 0:59

answered Mar 2 '14 at 16:06

speigg

1,420195

edited Aug 15 '18 at 0:59

answered Mar 2 '14 at 16:06

speigg

1,420195

answered Mar 2 '14 at 16:06

speigg

1,420195

answered Mar 2 '14 at 16:06

speigg

1,420195

7

using reduce is an excellent solution (one can also use _.reduce() from the underscore or lodash library)

– Alp
May 22 '14 at 14:51

2

I think self is probably undefined here. Do you mean this?

– Platinum Azure
Jun 17 '14 at 3:37

2

No, self is defined. this would be incorrect.

– speigg
Jun 18 '14 at 16:03

6

@PlatinumAzure developer.mozilla.org/en-US/docs/Web/API/Window.self

– Rahil Wazir
Nov 7 '14 at 10:15

1

Here's my complement to set values by path: pastebin.com/jDp5sKT9

– mroach
Jan 2 '17 at 8:42

|
show 6 more comments

7

using reduce is an excellent solution (one can also use _.reduce() from the underscore or lodash library)

– Alp
May 22 '14 at 14:51

2

I think self is probably undefined here. Do you mean this?

– Platinum Azure
Jun 17 '14 at 3:37

2

No, self is defined. this would be incorrect.

– speigg
Jun 18 '14 at 16:03

6

@PlatinumAzure developer.mozilla.org/en-US/docs/Web/API/Window.self

– Rahil Wazir
Nov 7 '14 at 10:15

1

Here's my complement to set values by path: pastebin.com/jDp5sKT9

– mroach
Jan 2 '17 at 8:42

using reduce is an excellent solution (one can also use _.reduce() from the underscore or lodash library)

– Alp
May 22 '14 at 14:51

I think self is probably undefined here. Do you mean this?

– Platinum Azure
Jun 17 '14 at 3:37

No, self is defined. this would be incorrect.

– speigg
Jun 18 '14 at 16:03

@PlatinumAzure developer.mozilla.org/en-US/docs/Web/API/Window.self

– Rahil Wazir
Nov 7 '14 at 10:15

Here's my complement to set values by path: pastebin.com/jDp5sKT9

– mroach
Jan 2 '17 at 8:42

|
show 6 more comments

125

This is now supported by lodash using _.get(obj, property). See https://lodash.com/docs#get

Example from the docs:

var object = { 'a': [{ 'b': { 'c': 3 } }] };



_.get(object, 'a[0].b.c');

// → 3



_.get(object, ['a', '0', 'b', 'c']);

// → 3



_.get(object, 'a.b.c', 'default');

// → 'default'

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

5

This should be the only accepted answer, because this is the only one working for both dot and bracket syntax and It doesn't fail, when we have '' in the string of a key in the path.

– Capaj
Aug 4 '15 at 2:12

5

This. Plus, it supports _.set(...)

– Josh C.
Aug 22 '17 at 6:23

what happes if the objet is not found?

– DDave
Oct 31 '17 at 16:58

@DDave if the value passed as the object is undefined or not an object, _.get will show the same behavior as when no key is found in the provided object. eg _.get(null, "foo") -> undefined, _.get(null, "foo", "bar") -> "bar". However this behavior is not defined in the docs so subject to change.

– Ian Walker-Sperber
Nov 2 '17 at 0:40

1

@Capaj you kiddin'? And who doesn't want/can't use lodash?

– Andre Figueiredo
Feb 19 '18 at 21:21

add a comment |

125

This is now supported by lodash using _.get(obj, property). See https://lodash.com/docs#get

Example from the docs:

var object = { 'a': [{ 'b': { 'c': 3 } }] };



_.get(object, 'a[0].b.c');

// → 3



_.get(object, ['a', '0', 'b', 'c']);

// → 3



_.get(object, 'a.b.c', 'default');

// → 'default'

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

5

This should be the only accepted answer, because this is the only one working for both dot and bracket syntax and It doesn't fail, when we have '' in the string of a key in the path.

– Capaj
Aug 4 '15 at 2:12

5

This. Plus, it supports _.set(...)

– Josh C.
Aug 22 '17 at 6:23

what happes if the objet is not found?

– DDave
Oct 31 '17 at 16:58

@DDave if the value passed as the object is undefined or not an object, _.get will show the same behavior as when no key is found in the provided object. eg _.get(null, "foo") -> undefined, _.get(null, "foo", "bar") -> "bar". However this behavior is not defined in the docs so subject to change.

– Ian Walker-Sperber
Nov 2 '17 at 0:40

1

@Capaj you kiddin'? And who doesn't want/can't use lodash?

– Andre Figueiredo
Feb 19 '18 at 21:21

add a comment |

125

This is now supported by lodash using _.get(obj, property). See https://lodash.com/docs#get

Example from the docs:

var object = { 'a': [{ 'b': { 'c': 3 } }] };



_.get(object, 'a[0].b.c');

// → 3



_.get(object, ['a', '0', 'b', 'c']);

// → 3



_.get(object, 'a.b.c', 'default');

// → 'default'

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

This is now supported by lodash using _.get(obj, property). See https://lodash.com/docs#get

Example from the docs:

var object = { 'a': [{ 'b': { 'c': 3 } }] };



_.get(object, 'a[0].b.c');

// → 3



_.get(object, ['a', '0', 'b', 'c']);

// → 3



_.get(object, 'a.b.c', 'default');

// → 'default'

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

answered Jul 8 '15 at 20:59

Ian Walker-Sperber

1,6582915

5

This should be the only accepted answer, because this is the only one working for both dot and bracket syntax and It doesn't fail, when we have '' in the string of a key in the path.

– Capaj
Aug 4 '15 at 2:12

5

This. Plus, it supports _.set(...)

– Josh C.
Aug 22 '17 at 6:23

what happes if the objet is not found?

– DDave
Oct 31 '17 at 16:58

@DDave if the value passed as the object is undefined or not an object, _.get will show the same behavior as when no key is found in the provided object. eg _.get(null, "foo") -> undefined, _.get(null, "foo", "bar") -> "bar". However this behavior is not defined in the docs so subject to change.

– Ian Walker-Sperber
Nov 2 '17 at 0:40

1

@Capaj you kiddin'? And who doesn't want/can't use lodash?

– Andre Figueiredo
Feb 19 '18 at 21:21

add a comment |

5

This should be the only accepted answer, because this is the only one working for both dot and bracket syntax and It doesn't fail, when we have '' in the string of a key in the path.

– Capaj
Aug 4 '15 at 2:12

5

This. Plus, it supports _.set(...)

– Josh C.
Aug 22 '17 at 6:23

what happes if the objet is not found?

– DDave
Oct 31 '17 at 16:58

@DDave if the value passed as the object is undefined or not an object, _.get will show the same behavior as when no key is found in the provided object. eg _.get(null, "foo") -> undefined, _.get(null, "foo", "bar") -> "bar". However this behavior is not defined in the docs so subject to change.

– Ian Walker-Sperber
Nov 2 '17 at 0:40

1

@Capaj you kiddin'? And who doesn't want/can't use lodash?

– Andre Figueiredo
Feb 19 '18 at 21:21

This should be the only accepted answer, because this is the only one working for both dot and bracket syntax and It doesn't fail, when we have '' in the string of a key in the path.

– Capaj
Aug 4 '15 at 2:12

This. Plus, it supports _.set(...)

– Josh C.
Aug 22 '17 at 6:23

what happes if the objet is not found?

– DDave
Oct 31 '17 at 16:58

@DDave if the value passed as the object is undefined or not an object, _.get will show the same behavior as when no key is found in the provided object. eg _.get(null, "foo") -> undefined, _.get(null, "foo", "bar") -> "bar". However this behavior is not defined in the docs so subject to change.

– Ian Walker-Sperber
Nov 2 '17 at 0:40

@Capaj you kiddin'? And who doesn't want/can't use lodash?

– Andre Figueiredo
Feb 19 '18 at 21:21

add a comment |

You'd have to parse the string yourself:

function getProperty(obj, prop) {

    var parts = prop.split('.');



    if (Array.isArray(parts)) {

        var last = parts.pop(),

        l = parts.length,

        i = 1,

        current = parts[0];



        while((obj = obj[current]) && i < l) {

            current = parts[i];

            i++;

        }



        if(obj) {

            return obj[last];

        }

    } else {

        throw 'parts is not valid array';

    }

}

This required that you also define array indexes with dot notation:

var part3name1 = "part3.0.name";

It makes the parsing easier.

DEMO

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

@Felix Kling : Your solution does provide me with what I need. And I thank you alot for that. But Alnitak also provide different ways and seem to work either. Since I can only choose one answer, I will choose Alnitak answer. Not that his solution is better than you or something like that. Anyway, I really appreciate your solution and effort you gave.

– Komaruloh
Jun 27 '11 at 11:25

1

@Komaruloh: Oh I thought you can always up vote answers on your own question.... anyway I was more or less kidding, I don't need more reputation ;) Happy coding!

– Felix Kling
Jun 27 '11 at 11:50

1

@Felix Kling : You need at least 15 reputation to up vote. :) I believe you don't need more reputation with 69k+ . Thanks

– Komaruloh
Jun 27 '11 at 14:58

@Felix FWIW - converting from syntax to property syntax is pretty trivial.

– Alnitak
Jun 27 '11 at 16:19

4

If you change the while loop to while (l > 0 && (obj = obj[current]) && i < l) then this code works for strings without dots as well.

– Snea
Aug 17 '14 at 6:18

|
show 2 more comments

You'd have to parse the string yourself:

function getProperty(obj, prop) {

    var parts = prop.split('.');



    if (Array.isArray(parts)) {

        var last = parts.pop(),

        l = parts.length,

        i = 1,

        current = parts[0];



        while((obj = obj[current]) && i < l) {

            current = parts[i];

            i++;

        }



        if(obj) {

            return obj[last];

        }

    } else {

        throw 'parts is not valid array';

    }

}

This required that you also define array indexes with dot notation:

var part3name1 = "part3.0.name";

It makes the parsing easier.

DEMO

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

@Felix Kling : Your solution does provide me with what I need. And I thank you alot for that. But Alnitak also provide different ways and seem to work either. Since I can only choose one answer, I will choose Alnitak answer. Not that his solution is better than you or something like that. Anyway, I really appreciate your solution and effort you gave.

– Komaruloh
Jun 27 '11 at 11:25

1

@Komaruloh: Oh I thought you can always up vote answers on your own question.... anyway I was more or less kidding, I don't need more reputation ;) Happy coding!

– Felix Kling
Jun 27 '11 at 11:50

1

@Felix Kling : You need at least 15 reputation to up vote. :) I believe you don't need more reputation with 69k+ . Thanks

– Komaruloh
Jun 27 '11 at 14:58

@Felix FWIW - converting from syntax to property syntax is pretty trivial.

– Alnitak
Jun 27 '11 at 16:19

4

If you change the while loop to while (l > 0 && (obj = obj[current]) && i < l) then this code works for strings without dots as well.

– Snea
Aug 17 '14 at 6:18

|
show 2 more comments

You'd have to parse the string yourself:

function getProperty(obj, prop) {

    var parts = prop.split('.');



    if (Array.isArray(parts)) {

        var last = parts.pop(),

        l = parts.length,

        i = 1,

        current = parts[0];



        while((obj = obj[current]) && i < l) {

            current = parts[i];

            i++;

        }



        if(obj) {

            return obj[last];

        }

    } else {

        throw 'parts is not valid array';

    }

}

This required that you also define array indexes with dot notation:

var part3name1 = "part3.0.name";

It makes the parsing easier.

DEMO

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

You'd have to parse the string yourself:

function getProperty(obj, prop) {

    var parts = prop.split('.');



    if (Array.isArray(parts)) {

        var last = parts.pop(),

        l = parts.length,

        i = 1,

        current = parts[0];



        while((obj = obj[current]) && i < l) {

            current = parts[i];

            i++;

        }



        if(obj) {

            return obj[last];

        }

    } else {

        throw 'parts is not valid array';

    }

}

This required that you also define array indexes with dot notation:

var part3name1 = "part3.0.name";

It makes the parsing easier.

DEMO

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

edited Dec 4 '15 at 13:46

d.danailov

7,10444230

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

answered Jun 27 '11 at 10:38

Felix Kling

549k126853910

@Felix Kling : Your solution does provide me with what I need. And I thank you alot for that. But Alnitak also provide different ways and seem to work either. Since I can only choose one answer, I will choose Alnitak answer. Not that his solution is better than you or something like that. Anyway, I really appreciate your solution and effort you gave.

– Komaruloh
Jun 27 '11 at 11:25

1

@Komaruloh: Oh I thought you can always up vote answers on your own question.... anyway I was more or less kidding, I don't need more reputation ;) Happy coding!

– Felix Kling
Jun 27 '11 at 11:50

1

@Felix Kling : You need at least 15 reputation to up vote. :) I believe you don't need more reputation with 69k+ . Thanks

– Komaruloh
Jun 27 '11 at 14:58

@Felix FWIW - converting from syntax to property syntax is pretty trivial.

– Alnitak
Jun 27 '11 at 16:19

4

If you change the while loop to while (l > 0 && (obj = obj[current]) && i < l) then this code works for strings without dots as well.

– Snea
Aug 17 '14 at 6:18

|
show 2 more comments

@Felix Kling : Your solution does provide me with what I need. And I thank you alot for that. But Alnitak also provide different ways and seem to work either. Since I can only choose one answer, I will choose Alnitak answer. Not that his solution is better than you or something like that. Anyway, I really appreciate your solution and effort you gave.

– Komaruloh
Jun 27 '11 at 11:25

1

@Komaruloh: Oh I thought you can always up vote answers on your own question.... anyway I was more or less kidding, I don't need more reputation ;) Happy coding!

– Felix Kling
Jun 27 '11 at 11:50

1

@Felix Kling : You need at least 15 reputation to up vote. :) I believe you don't need more reputation with 69k+ . Thanks

– Komaruloh
Jun 27 '11 at 14:58

@Felix FWIW - converting from syntax to property syntax is pretty trivial.

– Alnitak
Jun 27 '11 at 16:19

4

If you change the while loop to while (l > 0 && (obj = obj[current]) && i < l) then this code works for strings without dots as well.

– Snea
Aug 17 '14 at 6:18

@Felix Kling : Your solution does provide me with what I need. And I thank you alot for that. But Alnitak also provide different ways and seem to work either. Since I can only choose one answer, I will choose Alnitak answer. Not that his solution is better than you or something like that. Anyway, I really appreciate your solution and effort you gave.

– Komaruloh
Jun 27 '11 at 11:25

@Komaruloh: Oh I thought you can always up vote answers on your own question.... anyway I was more or less kidding, I don't need more reputation ;) Happy coding!

– Felix Kling
Jun 27 '11 at 11:50

@Felix Kling : You need at least 15 reputation to up vote. :) I believe you don't need more reputation with 69k+ . Thanks

– Komaruloh
Jun 27 '11 at 14:58

@Felix FWIW - converting from syntax to property syntax is pretty trivial.

– Alnitak
Jun 27 '11 at 16:19

If you change the while loop to while (l > 0 && (obj = obj[current]) && i < l) then this code works for strings without dots as well.

– Snea
Aug 17 '14 at 6:18

|
show 2 more comments

Works for arrays / arrays inside the object also.
Defensive against invalid values.

/**

 * Retrieve nested item from object/array

 * @param {Object|Array} obj

 * @param {String} path dot separated

 * @param {*} def default value ( if result undefined )

 * @returns {*}

 */

function path(obj, path, def){

    var i, len;



    for(i = 0,path = path.split('.'), len = path.length; i < len; i++){

        if(!obj || typeof obj !== 'object') return def;

        obj = obj[path[i]];

    }



    if(obj === undefined) return def;

    return obj;

}



//////////////////////////

//         TEST         //

//////////////////////////



var arr = [true, {'sp ace': true}, true]



var obj = {

  'sp ace': true,

  arr: arr,

  nested: {'dotted.str.ing': true},

  arr3: arr

}



shouldThrow(`path(obj, "arr.0")`);

shouldBeDefined(`path(obj, "arr[0]")`);

shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);

shouldBeTrue(`path(obj, "sp ace")`);

shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");

shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);

<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>

edited Mar 27 '16 at 10:47

Endless

12.2k65070

answered Apr 24 '13 at 11:24

TheZver

7462915

9

Thanks this is the best and most performant answer - jsfiddle.net/Jw8XB/1

– Dominic
Jul 31 '13 at 23:00

@Endless, I'd like to emphasize the path should separate the items with dots. Braces won't work. I.e. to access first item in array use "0.sp ace".

– TheZver
Mar 27 '16 at 11:32

add a comment |

Works for arrays / arrays inside the object also.
Defensive against invalid values.

/**

 * Retrieve nested item from object/array

 * @param {Object|Array} obj

 * @param {String} path dot separated

 * @param {*} def default value ( if result undefined )

 * @returns {*}

 */

function path(obj, path, def){

    var i, len;



    for(i = 0,path = path.split('.'), len = path.length; i < len; i++){

        if(!obj || typeof obj !== 'object') return def;

        obj = obj[path[i]];

    }



    if(obj === undefined) return def;

    return obj;

}



//////////////////////////

//         TEST         //

//////////////////////////



var arr = [true, {'sp ace': true}, true]



var obj = {

  'sp ace': true,

  arr: arr,

  nested: {'dotted.str.ing': true},

  arr3: arr

}



shouldThrow(`path(obj, "arr.0")`);

shouldBeDefined(`path(obj, "arr[0]")`);

shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);

shouldBeTrue(`path(obj, "sp ace")`);

shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");

shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);

<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>

edited Mar 27 '16 at 10:47

Endless

12.2k65070

answered Apr 24 '13 at 11:24

TheZver

7462915

9

Thanks this is the best and most performant answer - jsfiddle.net/Jw8XB/1

– Dominic
Jul 31 '13 at 23:00

@Endless, I'd like to emphasize the path should separate the items with dots. Braces won't work. I.e. to access first item in array use "0.sp ace".

– TheZver
Mar 27 '16 at 11:32

add a comment |

Works for arrays / arrays inside the object also.
Defensive against invalid values.

/**

 * Retrieve nested item from object/array

 * @param {Object|Array} obj

 * @param {String} path dot separated

 * @param {*} def default value ( if result undefined )

 * @returns {*}

 */

function path(obj, path, def){

    var i, len;



    for(i = 0,path = path.split('.'), len = path.length; i < len; i++){

        if(!obj || typeof obj !== 'object') return def;

        obj = obj[path[i]];

    }



    if(obj === undefined) return def;

    return obj;

}



//////////////////////////

//         TEST         //

//////////////////////////



var arr = [true, {'sp ace': true}, true]



var obj = {

  'sp ace': true,

  arr: arr,

  nested: {'dotted.str.ing': true},

  arr3: arr

}



shouldThrow(`path(obj, "arr.0")`);

shouldBeDefined(`path(obj, "arr[0]")`);

shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);

shouldBeTrue(`path(obj, "sp ace")`);

shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");

shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);

<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>

edited Mar 27 '16 at 10:47

Endless

12.2k65070

answered Apr 24 '13 at 11:24

TheZver

7462915

Works for arrays / arrays inside the object also.
Defensive against invalid values.

/**

 * Retrieve nested item from object/array

 * @param {Object|Array} obj

 * @param {String} path dot separated

 * @param {*} def default value ( if result undefined )

 * @returns {*}

 */

function path(obj, path, def){

    var i, len;



    for(i = 0,path = path.split('.'), len = path.length; i < len; i++){

        if(!obj || typeof obj !== 'object') return def;

        obj = obj[path[i]];

    }



    if(obj === undefined) return def;

    return obj;

}



//////////////////////////

//         TEST         //

//////////////////////////



var arr = [true, {'sp ace': true}, true]



var obj = {

  'sp ace': true,

  arr: arr,

  nested: {'dotted.str.ing': true},

  arr3: arr

}



shouldThrow(`path(obj, "arr.0")`);

shouldBeDefined(`path(obj, "arr[0]")`);

shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);

shouldBeTrue(`path(obj, "sp ace")`);

shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");

shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);

<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>

/**

 * Retrieve nested item from object/array

 * @param {Object|Array} obj

 * @param {String} path dot separated

 * @param {*} def default value ( if result undefined )

 * @returns {*}

 */

function path(obj, path, def){

    var i, len;



    for(i = 0,path = path.split('.'), len = path.length; i < len; i++){

        if(!obj || typeof obj !== 'object') return def;

        obj = obj[path[i]];

    }



    if(obj === undefined) return def;

    return obj;

}



//////////////////////////

//         TEST         //

//////////////////////////



var arr = [true, {'sp ace': true}, true]



var obj = {

  'sp ace': true,

  arr: arr,

  nested: {'dotted.str.ing': true},

  arr3: arr

}



shouldThrow(`path(obj, "arr.0")`);

shouldBeDefined(`path(obj, "arr[0]")`);

shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);

shouldBeTrue(`path(obj, "sp ace")`);

shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");

shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);

<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>

/**

 * Retrieve nested item from object/array

 * @param {Object|Array} obj

 * @param {String} path dot separated

 * @param {*} def default value ( if result undefined )

 * @returns {*}

 */

function path(obj, path, def){

    var i, len;



    for(i = 0,path = path.split('.'), len = path.length; i < len; i++){

        if(!obj || typeof obj !== 'object') return def;

        obj = obj[path[i]];

    }



    if(obj === undefined) return def;

    return obj;

}



//////////////////////////

//         TEST         //

//////////////////////////



var arr = [true, {'sp ace': true}, true]



var obj = {

  'sp ace': true,

  arr: arr,

  nested: {'dotted.str.ing': true},

  arr3: arr

}



shouldThrow(`path(obj, "arr.0")`);

shouldBeDefined(`path(obj, "arr[0]")`);

shouldBeEqualToNumber(`path(obj, "arr.length")`, 3);

shouldBeTrue(`path(obj, "sp ace")`);

shouldBeEqualToString(`path(obj, "none.existed.prop", "fallback")`, "fallback");

shouldBeTrue(`path(obj, "nested['dotted.str.ing'])`);

<script src="https://cdn.rawgit.com/coderek/e7b30bac7634a50ad8fd/raw/174b6634c8f57aa8aac0716c5b7b2a7098e03584/js-test.js"></script>

edited Mar 27 '16 at 10:47

Endless

12.2k65070

answered Apr 24 '13 at 11:24

TheZver

7462915

edited Mar 27 '16 at 10:47

Endless

12.2k65070

edited Mar 27 '16 at 10:47

Endless

12.2k65070

edited Mar 27 '16 at 10:47

Endless

12.2k65070

answered Apr 24 '13 at 11:24

TheZver

7462915

answered Apr 24 '13 at 11:24

TheZver

7462915

answered Apr 24 '13 at 11:24

TheZver

7462915

9

Thanks this is the best and most performant answer - jsfiddle.net/Jw8XB/1

– Dominic
Jul 31 '13 at 23:00

@Endless, I'd like to emphasize the path should separate the items with dots. Braces won't work. I.e. to access first item in array use "0.sp ace".

– TheZver
Mar 27 '16 at 11:32

add a comment |

9

Thanks this is the best and most performant answer - jsfiddle.net/Jw8XB/1

– Dominic
Jul 31 '13 at 23:00

@Endless, I'd like to emphasize the path should separate the items with dots. Braces won't work. I.e. to access first item in array use "0.sp ace".

– TheZver
Mar 27 '16 at 11:32

Thanks this is the best and most performant answer - jsfiddle.net/Jw8XB/1

– Dominic
Jul 31 '13 at 23:00

@Endless, I'd like to emphasize the path should separate the items with dots. Braces won't work. I.e. to access first item in array use "0.sp ace".

– TheZver
Mar 27 '16 at 11:32

add a comment |

ES6: Only one line in Vanila JS (it return null if don't find instead of giving error):

'path.string'.split('.').reduce((p,c)=>p&&p[c]||null, MyOBJ)

or exemple:

'a.b.c'.split('.').reduce((p,c)=>p&&p[c]||null, {a:{b:{c:1}}})

For a ready to use function that also recognizes false, 0 and negative number and accept default values as parameter:

const resolvePath = (object, path, defaultValue) => path

   .split('.')

   .reduce((o, p) => o ? o[p] : defaultValue, object)

Exemple to use:

resolvePath(window,'document.body') => <body>

resolvePath(window,'document.body.xyz') => undefined

resolvePath(window,'document.body.xyz', null) => null

resolvePath(window,'document.body.xyz', 1) => 1

Bonus:

To set a path (Requested by @rob-gordon) you can use:

const setPath = (object, path, value) => path

   .split('.')

   .reduce((o,p) => o[p] = path.split('.').pop() === p ? value : o[p] || {}, object)

Example:

let myVar = {}

setPath(myVar, 'a.b.c', 42) => 42

console.log(myVar) => {a: {b: {c: 42}}}

Access array with :

const resolvePath = (object, path, defaultValue) => path

   .split(/[.[]'"]/)

   .filter(p => p)

   .reduce((o, p) => o ? o[p] : defaultValue, object)

exemple

const myVar = {a:{b:[{c:1}]}}

resolvePath(myVar,'a.b[0].c') => 1

resolvePath(myVar,'a["b"]['0'].c') => 1

edited Sep 19 '17 at 19:05

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

1

I love this technique. This is really messy but I wanted to use this technique for assignment. let o = {a:{b:{c:1}}}; let str = 'a.b.c'; str.split('.').splice(0, str.split('.').length - 1).reduce((p,c)=>p&&p[c]||null, o)[str.split('.').slice(-1)] = "some new value";

– rob-gordon
Jun 28 '17 at 17:15

1

I like the idea of using reduce but your logic seems off for 0, undefined and null values. {a:{b:{c:0}}} returns null instead of 0. Perhaps explicitly checking for null or undefined will clear up these issues. (p,c)=>p === undefined || p === null ? undefined : p[c]

– SmujMaiku
Oct 15 '17 at 17:31

Hi @SmujMaiku, the "ready to use" function return correctly for '0', 'undefined' and 'null', I just tested on the console: resolvePath({a:{b:{c:0}}},'a.b.c',null) => 0; It check if the key exists instead of the value itself which avoid more than one check

– Adriano Spadoni
Oct 16 '17 at 9:18

here defaultValue did not work, using Reflect.has(o, k) ? ... (ES6 Reflect.has) worked though

– Andre Figueiredo
Feb 23 '18 at 12:31

add a comment |

ES6: Only one line in Vanila JS (it return null if don't find instead of giving error):

'path.string'.split('.').reduce((p,c)=>p&&p[c]||null, MyOBJ)

or exemple:

'a.b.c'.split('.').reduce((p,c)=>p&&p[c]||null, {a:{b:{c:1}}})

For a ready to use function that also recognizes false, 0 and negative number and accept default values as parameter:

const resolvePath = (object, path, defaultValue) => path

   .split('.')

   .reduce((o, p) => o ? o[p] : defaultValue, object)

Exemple to use:

resolvePath(window,'document.body') => <body>

resolvePath(window,'document.body.xyz') => undefined

resolvePath(window,'document.body.xyz', null) => null

resolvePath(window,'document.body.xyz', 1) => 1

Bonus:

To set a path (Requested by @rob-gordon) you can use:

const setPath = (object, path, value) => path

   .split('.')

   .reduce((o,p) => o[p] = path.split('.').pop() === p ? value : o[p] || {}, object)

Example:

let myVar = {}

setPath(myVar, 'a.b.c', 42) => 42

console.log(myVar) => {a: {b: {c: 42}}}

Access array with :

const resolvePath = (object, path, defaultValue) => path

   .split(/[.[]'"]/)

   .filter(p => p)

   .reduce((o, p) => o ? o[p] : defaultValue, object)

exemple

const myVar = {a:{b:[{c:1}]}}

resolvePath(myVar,'a.b[0].c') => 1

resolvePath(myVar,'a["b"]['0'].c') => 1

edited Sep 19 '17 at 19:05

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

1

I love this technique. This is really messy but I wanted to use this technique for assignment. let o = {a:{b:{c:1}}}; let str = 'a.b.c'; str.split('.').splice(0, str.split('.').length - 1).reduce((p,c)=>p&&p[c]||null, o)[str.split('.').slice(-1)] = "some new value";

– rob-gordon
Jun 28 '17 at 17:15

1

I like the idea of using reduce but your logic seems off for 0, undefined and null values. {a:{b:{c:0}}} returns null instead of 0. Perhaps explicitly checking for null or undefined will clear up these issues. (p,c)=>p === undefined || p === null ? undefined : p[c]

– SmujMaiku
Oct 15 '17 at 17:31

Hi @SmujMaiku, the "ready to use" function return correctly for '0', 'undefined' and 'null', I just tested on the console: resolvePath({a:{b:{c:0}}},'a.b.c',null) => 0; It check if the key exists instead of the value itself which avoid more than one check

– Adriano Spadoni
Oct 16 '17 at 9:18

here defaultValue did not work, using Reflect.has(o, k) ? ... (ES6 Reflect.has) worked though

– Andre Figueiredo
Feb 23 '18 at 12:31

add a comment |

ES6: Only one line in Vanila JS (it return null if don't find instead of giving error):

'path.string'.split('.').reduce((p,c)=>p&&p[c]||null, MyOBJ)

or exemple:

'a.b.c'.split('.').reduce((p,c)=>p&&p[c]||null, {a:{b:{c:1}}})

For a ready to use function that also recognizes false, 0 and negative number and accept default values as parameter:

const resolvePath = (object, path, defaultValue) => path

   .split('.')

   .reduce((o, p) => o ? o[p] : defaultValue, object)

Exemple to use:

resolvePath(window,'document.body') => <body>

resolvePath(window,'document.body.xyz') => undefined

resolvePath(window,'document.body.xyz', null) => null

resolvePath(window,'document.body.xyz', 1) => 1

Bonus:

To set a path (Requested by @rob-gordon) you can use:

const setPath = (object, path, value) => path

   .split('.')

   .reduce((o,p) => o[p] = path.split('.').pop() === p ? value : o[p] || {}, object)

Example:

let myVar = {}

setPath(myVar, 'a.b.c', 42) => 42

console.log(myVar) => {a: {b: {c: 42}}}

Access array with :

const resolvePath = (object, path, defaultValue) => path

   .split(/[.[]'"]/)

   .filter(p => p)

   .reduce((o, p) => o ? o[p] : defaultValue, object)

exemple

const myVar = {a:{b:[{c:1}]}}

resolvePath(myVar,'a.b[0].c') => 1

resolvePath(myVar,'a["b"]['0'].c') => 1

edited Sep 19 '17 at 19:05

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

ES6: Only one line in Vanila JS (it return null if don't find instead of giving error):

'path.string'.split('.').reduce((p,c)=>p&&p[c]||null, MyOBJ)

or exemple:

'a.b.c'.split('.').reduce((p,c)=>p&&p[c]||null, {a:{b:{c:1}}})

For a ready to use function that also recognizes false, 0 and negative number and accept default values as parameter:

const resolvePath = (object, path, defaultValue) => path

   .split('.')

   .reduce((o, p) => o ? o[p] : defaultValue, object)

Exemple to use:

resolvePath(window,'document.body') => <body>

resolvePath(window,'document.body.xyz') => undefined

resolvePath(window,'document.body.xyz', null) => null

resolvePath(window,'document.body.xyz', 1) => 1

Bonus:

To set a path (Requested by @rob-gordon) you can use:

const setPath = (object, path, value) => path

   .split('.')

   .reduce((o,p) => o[p] = path.split('.').pop() === p ? value : o[p] || {}, object)

Example:

let myVar = {}

setPath(myVar, 'a.b.c', 42) => 42

console.log(myVar) => {a: {b: {c: 42}}}

Access array with :

const resolvePath = (object, path, defaultValue) => path

   .split(/[.[]'"]/)

   .filter(p => p)

   .reduce((o, p) => o ? o[p] : defaultValue, object)

exemple

const myVar = {a:{b:[{c:1}]}}

resolvePath(myVar,'a.b[0].c') => 1

resolvePath(myVar,'a["b"]['0'].c') => 1

edited Sep 19 '17 at 19:05

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

edited Sep 19 '17 at 19:05

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

answered May 8 '17 at 13:38

Adriano Spadoni

2,1051925

1

I love this technique. This is really messy but I wanted to use this technique for assignment. let o = {a:{b:{c:1}}}; let str = 'a.b.c'; str.split('.').splice(0, str.split('.').length - 1).reduce((p,c)=>p&&p[c]||null, o)[str.split('.').slice(-1)] = "some new value";

– rob-gordon
Jun 28 '17 at 17:15

1

I like the idea of using reduce but your logic seems off for 0, undefined and null values. {a:{b:{c:0}}} returns null instead of 0. Perhaps explicitly checking for null or undefined will clear up these issues. (p,c)=>p === undefined || p === null ? undefined : p[c]

– SmujMaiku
Oct 15 '17 at 17:31

Hi @SmujMaiku, the "ready to use" function return correctly for '0', 'undefined' and 'null', I just tested on the console: resolvePath({a:{b:{c:0}}},'a.b.c',null) => 0; It check if the key exists instead of the value itself which avoid more than one check

– Adriano Spadoni
Oct 16 '17 at 9:18

here defaultValue did not work, using Reflect.has(o, k) ? ... (ES6 Reflect.has) worked though

– Andre Figueiredo
Feb 23 '18 at 12:31

add a comment |

1

I love this technique. This is really messy but I wanted to use this technique for assignment. let o = {a:{b:{c:1}}}; let str = 'a.b.c'; str.split('.').splice(0, str.split('.').length - 1).reduce((p,c)=>p&&p[c]||null, o)[str.split('.').slice(-1)] = "some new value";

– rob-gordon
Jun 28 '17 at 17:15

1

I like the idea of using reduce but your logic seems off for 0, undefined and null values. {a:{b:{c:0}}} returns null instead of 0. Perhaps explicitly checking for null or undefined will clear up these issues. (p,c)=>p === undefined || p === null ? undefined : p[c]

– SmujMaiku
Oct 15 '17 at 17:31

Hi @SmujMaiku, the "ready to use" function return correctly for '0', 'undefined' and 'null', I just tested on the console: resolvePath({a:{b:{c:0}}},'a.b.c',null) => 0; It check if the key exists instead of the value itself which avoid more than one check

– Adriano Spadoni
Oct 16 '17 at 9:18

here defaultValue did not work, using Reflect.has(o, k) ? ... (ES6 Reflect.has) worked though

– Andre Figueiredo
Feb 23 '18 at 12:31

I love this technique. This is really messy but I wanted to use this technique for assignment.

let o = {a:{b:{c:1}}}; let str = 'a.b.c'; str.split('.').splice(0, str.split('.').length - 1).reduce((p,c)=>p&&p[c]||null, o)[str.split('.').slice(-1)] = "some new value";

– rob-gordon
Jun 28 '17 at 17:15

I love this technique. This is really messy but I wanted to use this technique for assignment.

let o = {a:{b:{c:1}}}; let str = 'a.b.c'; str.split('.').splice(0, str.split('.').length - 1).reduce((p,c)=>p&&p[c]||null, o)[str.split('.').slice(-1)] = "some new value";

– rob-gordon
Jun 28 '17 at 17:15

I like the idea of using reduce but your logic seems off for 0, undefined and null values. {a:{b:{c:0}}} returns null instead of 0. Perhaps explicitly checking for null or undefined will clear up these issues. (p,c)=>p === undefined || p === null ? undefined : p[c]

– SmujMaiku
Oct 15 '17 at 17:31

Hi @SmujMaiku, the "ready to use" function return correctly for '0', 'undefined' and 'null', I just tested on the console: resolvePath({a:{b:{c:0}}},'a.b.c',null) => 0; It check if the key exists instead of the value itself which avoid more than one check

– Adriano Spadoni
Oct 16 '17 at 9:18

here defaultValue did not work, using Reflect.has(o, k) ? ... (ES6 Reflect.has) worked though

– Andre Figueiredo
Feb 23 '18 at 12:31

add a comment |

using eval:

var part1name = eval("someObject.part1.name");

wrap to return undefined on error

function path(obj, path) {

    try {

        return eval("obj." + path);

    } catch(e) {

        return undefined;

    }

}

http://jsfiddle.net/shanimal/b3xTw/

Please use common sense and caution when wielding the power of eval. It's a bit like a light saber, if you turn it on there's a 90% chance you'll sever a limb. Its not for everybody.

edited Apr 24 '14 at 6:55

community wiki

5 revs, 2 users 91%
Shanimal

5

Whether or not eval is a good idea depends on where the property string data is coming from. I doubt you have any reason to be concerned for hackers breaking in via a static "var p='a.b.c';eval(p);" type call. It's a perfectly fine idea for that.

– James Wilkins
Aug 21 '14 at 22:39

add a comment |

using eval:

var part1name = eval("someObject.part1.name");

wrap to return undefined on error

function path(obj, path) {

    try {

        return eval("obj." + path);

    } catch(e) {

        return undefined;

    }

}

http://jsfiddle.net/shanimal/b3xTw/

Please use common sense and caution when wielding the power of eval. It's a bit like a light saber, if you turn it on there's a 90% chance you'll sever a limb. Its not for everybody.

edited Apr 24 '14 at 6:55

community wiki

5 revs, 2 users 91%
Shanimal

5

Whether or not eval is a good idea depends on where the property string data is coming from. I doubt you have any reason to be concerned for hackers breaking in via a static "var p='a.b.c';eval(p);" type call. It's a perfectly fine idea for that.

– James Wilkins
Aug 21 '14 at 22:39

add a comment |

using eval:

var part1name = eval("someObject.part1.name");

wrap to return undefined on error

function path(obj, path) {

    try {

        return eval("obj." + path);

    } catch(e) {

        return undefined;

    }

}

http://jsfiddle.net/shanimal/b3xTw/

Please use common sense and caution when wielding the power of eval. It's a bit like a light saber, if you turn it on there's a 90% chance you'll sever a limb. Its not for everybody.

edited Apr 24 '14 at 6:55

community wiki

5 revs, 2 users 91%
Shanimal

using eval:

var part1name = eval("someObject.part1.name");

wrap to return undefined on error

function path(obj, path) {

    try {

        return eval("obj." + path);

    } catch(e) {

        return undefined;

    }

}

http://jsfiddle.net/shanimal/b3xTw/

Please use common sense and caution when wielding the power of eval. It's a bit like a light saber, if you turn it on there's a 90% chance you'll sever a limb. Its not for everybody.

edited Apr 24 '14 at 6:55

community wiki

5 revs, 2 users 91%
Shanimal

edited Apr 24 '14 at 6:55

community wiki

5 revs, 2 users 91%
Shanimal

community wiki

5 revs, 2 users 91%
Shanimal

community wiki

5 revs, 2 users 91%
Shanimal

5

Whether or not eval is a good idea depends on where the property string data is coming from. I doubt you have any reason to be concerned for hackers breaking in via a static "var p='a.b.c';eval(p);" type call. It's a perfectly fine idea for that.

– James Wilkins
Aug 21 '14 at 22:39

add a comment |

5

Whether or not eval is a good idea depends on where the property string data is coming from. I doubt you have any reason to be concerned for hackers breaking in via a static "var p='a.b.c';eval(p);" type call. It's a perfectly fine idea for that.

– James Wilkins
Aug 21 '14 at 22:39

Whether or not eval is a good idea depends on where the property string data is coming from. I doubt you have any reason to be concerned for hackers breaking in via a static "var p='a.b.c';eval(p);" type call. It's a perfectly fine idea for that.

– James Wilkins
Aug 21 '14 at 22:39

add a comment |

You can manage to obtain value of a deep object member with dot notation without any external JavaScript library with the simple following trick:

new Function('_', 'return _.' + path)(obj);

In your case to obtain value of part1.name from someObject just do:

new Function('_', 'return _.part1.name')(someObject);

Here is a simple fiddle demo: https://jsfiddle.net/harishanchu/oq5esowf/

edited Feb 24 '16 at 11:43

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

2

function deep_value ( obj, path ) { return new Function( 'o', 'return o.' + path )( obj ); }

– ArcangelZith
Jul 29 '16 at 4:59

add a comment |

You can manage to obtain value of a deep object member with dot notation without any external JavaScript library with the simple following trick:

new Function('_', 'return _.' + path)(obj);

In your case to obtain value of part1.name from someObject just do:

new Function('_', 'return _.part1.name')(someObject);

Here is a simple fiddle demo: https://jsfiddle.net/harishanchu/oq5esowf/

edited Feb 24 '16 at 11:43

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

2

function deep_value ( obj, path ) { return new Function( 'o', 'return o.' + path )( obj ); }

– ArcangelZith
Jul 29 '16 at 4:59

add a comment |

You can manage to obtain value of a deep object member with dot notation without any external JavaScript library with the simple following trick:

new Function('_', 'return _.' + path)(obj);

In your case to obtain value of part1.name from someObject just do:

new Function('_', 'return _.part1.name')(someObject);

Here is a simple fiddle demo: https://jsfiddle.net/harishanchu/oq5esowf/

edited Feb 24 '16 at 11:43

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

You can manage to obtain value of a deep object member with dot notation without any external JavaScript library with the simple following trick:

new Function('_', 'return _.' + path)(obj);

In your case to obtain value of part1.name from someObject just do:

new Function('_', 'return _.part1.name')(someObject);

Here is a simple fiddle demo: https://jsfiddle.net/harishanchu/oq5esowf/

edited Feb 24 '16 at 11:43

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

edited Feb 24 '16 at 11:43

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

answered Apr 11 '15 at 10:22

Harish Anchu

5,82941951

2

function deep_value ( obj, path ) { return new Function( 'o', 'return o.' + path )( obj ); }

– ArcangelZith
Jul 29 '16 at 4:59

add a comment |

2

function deep_value ( obj, path ) { return new Function( 'o', 'return o.' + path )( obj ); }

– ArcangelZith
Jul 29 '16 at 4:59

function deep_value ( obj, path ) { return new Function( 'o', 'return o.' + path )( obj ); }

– ArcangelZith
Jul 29 '16 at 4:59

add a comment |

Here I offer more ways, which seem faster in many respects:

Option 1: Split string on . or [ or ] or ' or ", reverse it, skip empty items.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var parts = path.split(/[|]|.|'|"/g).reverse(), name; // (why reverse? because it's usually faster to pop off the end of an array)

    while (parts.length) { name=parts.pop(); if (name) origin=origin[name]; }

    return origin;

}

Option 2 (fastest of all, except eval): Low level character scan (no regex/split/etc, just a quick char scan).
Note: This one does not support quotes for indexes.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c = '', pc, i = 0, n = path.length, name = '';

    if (n) while (i<=n) ((c = path[i++]) == '.' || c == '[' || c == ']' || c == void 0) ? (name?(origin = origin[name], name = ''):(pc=='.'||pc=='['||pc==']'&&c==']'?i=n+2:void 0),pc=c) : name += c;

    if (i==n+2) throw "Invalid path: "+path;

    return origin;

} // (around 1,000,000+/- ops/sec)

Option 3: (new: option 2 expanded to support quotes - a bit slower, but still fast)

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c, pc, i = 0, n = path.length, name = '', q;

    while (i<=n)

        ((c = path[i++]) == '.' || c == '[' || c == ']' || c == "'" || c == '"' || c == void 0) ? (c==q&&path[i]==']'?q='':q?name+=c:name?(origin?origin=origin[name]:i=n+2,name='') : (pc=='['&&(c=='"'||c=="'")?q=c:pc=='.'||pc=='['||pc==']'&&c==']'||pc=='"'||pc=="'"?i=n+2:void 0), pc=c) : name += c;

    if (i==n+2 || name) throw "Invalid path: "+path;

    return origin;

}

JSPerf: http://jsperf.com/ways-to-dereference-a-delimited-property-string/3

edited May 23 '17 at 11:55

Community♦

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

add a comment |

Here I offer more ways, which seem faster in many respects:

Option 1: Split string on . or [ or ] or ' or ", reverse it, skip empty items.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var parts = path.split(/[|]|.|'|"/g).reverse(), name; // (why reverse? because it's usually faster to pop off the end of an array)

    while (parts.length) { name=parts.pop(); if (name) origin=origin[name]; }

    return origin;

}

Option 2 (fastest of all, except eval): Low level character scan (no regex/split/etc, just a quick char scan).
Note: This one does not support quotes for indexes.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c = '', pc, i = 0, n = path.length, name = '';

    if (n) while (i<=n) ((c = path[i++]) == '.' || c == '[' || c == ']' || c == void 0) ? (name?(origin = origin[name], name = ''):(pc=='.'||pc=='['||pc==']'&&c==']'?i=n+2:void 0),pc=c) : name += c;

    if (i==n+2) throw "Invalid path: "+path;

    return origin;

} // (around 1,000,000+/- ops/sec)

Option 3: (new: option 2 expanded to support quotes - a bit slower, but still fast)

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c, pc, i = 0, n = path.length, name = '', q;

    while (i<=n)

        ((c = path[i++]) == '.' || c == '[' || c == ']' || c == "'" || c == '"' || c == void 0) ? (c==q&&path[i]==']'?q='':q?name+=c:name?(origin?origin=origin[name]:i=n+2,name='') : (pc=='['&&(c=='"'||c=="'")?q=c:pc=='.'||pc=='['||pc==']'&&c==']'||pc=='"'||pc=="'"?i=n+2:void 0), pc=c) : name += c;

    if (i==n+2 || name) throw "Invalid path: "+path;

    return origin;

}

JSPerf: http://jsperf.com/ways-to-dereference-a-delimited-property-string/3

edited May 23 '17 at 11:55

Community♦

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

add a comment |

Here I offer more ways, which seem faster in many respects:

Option 1: Split string on . or [ or ] or ' or ", reverse it, skip empty items.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var parts = path.split(/[|]|.|'|"/g).reverse(), name; // (why reverse? because it's usually faster to pop off the end of an array)

    while (parts.length) { name=parts.pop(); if (name) origin=origin[name]; }

    return origin;

}

Option 2 (fastest of all, except eval): Low level character scan (no regex/split/etc, just a quick char scan).
Note: This one does not support quotes for indexes.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c = '', pc, i = 0, n = path.length, name = '';

    if (n) while (i<=n) ((c = path[i++]) == '.' || c == '[' || c == ']' || c == void 0) ? (name?(origin = origin[name], name = ''):(pc=='.'||pc=='['||pc==']'&&c==']'?i=n+2:void 0),pc=c) : name += c;

    if (i==n+2) throw "Invalid path: "+path;

    return origin;

} // (around 1,000,000+/- ops/sec)

Option 3: (new: option 2 expanded to support quotes - a bit slower, but still fast)

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c, pc, i = 0, n = path.length, name = '', q;

    while (i<=n)

        ((c = path[i++]) == '.' || c == '[' || c == ']' || c == "'" || c == '"' || c == void 0) ? (c==q&&path[i]==']'?q='':q?name+=c:name?(origin?origin=origin[name]:i=n+2,name='') : (pc=='['&&(c=='"'||c=="'")?q=c:pc=='.'||pc=='['||pc==']'&&c==']'||pc=='"'||pc=="'"?i=n+2:void 0), pc=c) : name += c;

    if (i==n+2 || name) throw "Invalid path: "+path;

    return origin;

}

JSPerf: http://jsperf.com/ways-to-dereference-a-delimited-property-string/3

edited May 23 '17 at 11:55

Community♦

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

Here I offer more ways, which seem faster in many respects:

Option 1: Split string on . or [ or ] or ' or ", reverse it, skip empty items.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var parts = path.split(/[|]|.|'|"/g).reverse(), name; // (why reverse? because it's usually faster to pop off the end of an array)

    while (parts.length) { name=parts.pop(); if (name) origin=origin[name]; }

    return origin;

}

Option 2 (fastest of all, except eval): Low level character scan (no regex/split/etc, just a quick char scan).
Note: This one does not support quotes for indexes.

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c = '', pc, i = 0, n = path.length, name = '';

    if (n) while (i<=n) ((c = path[i++]) == '.' || c == '[' || c == ']' || c == void 0) ? (name?(origin = origin[name], name = ''):(pc=='.'||pc=='['||pc==']'&&c==']'?i=n+2:void 0),pc=c) : name += c;

    if (i==n+2) throw "Invalid path: "+path;

    return origin;

} // (around 1,000,000+/- ops/sec)

Option 3: (new: option 2 expanded to support quotes - a bit slower, but still fast)

function getValue(path, origin) {

    if (origin === void 0 || origin === null) origin = self ? self : this;

    if (typeof path !== 'string') path = '' + path;

    var c, pc, i = 0, n = path.length, name = '', q;

    while (i<=n)

        ((c = path[i++]) == '.' || c == '[' || c == ']' || c == "'" || c == '"' || c == void 0) ? (c==q&&path[i]==']'?q='':q?name+=c:name?(origin?origin=origin[name]:i=n+2,name='') : (pc=='['&&(c=='"'||c=="'")?q=c:pc=='.'||pc=='['||pc==']'&&c==']'||pc=='"'||pc=="'"?i=n+2:void 0), pc=c) : name += c;

    if (i==n+2 || name) throw "Invalid path: "+path;

    return origin;

}

JSPerf: http://jsperf.com/ways-to-dereference-a-delimited-property-string/3

edited May 23 '17 at 11:55

Community♦

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

edited May 23 '17 at 11:55

Community♦

edited May 23 '17 at 11:55

Community♦

edited May 23 '17 at 11:55

Community♦

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

answered Aug 21 '14 at 22:12

James Wilkins

3,1392235

add a comment |

This will probably never see the light of day... but here it is anyway.

Replace bracket syntax with .

Split on . character

Remove blank strings

Find the path (otherwise undefined)

// "one liner" (ES6)



const deep_value = (obj, path) => 

  path

    .replace(/[|].?/g, '.')

    .split('.')

    .filter(s => s)

    .reduce((acc, val) => acc && acc[val], obj);

    

// ... and that's it.



var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }

        // ...

    ]

};



console.log(deep_value(someObject, "part1.name"));               // Part 1

console.log(deep_value(someObject, "part2.qty"));                // 60

console.log(deep_value(someObject, "part3[0].name"));            // Part 3A

edited Nov 10 '18 at 13:24

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

1

It did see the light of the day!! thanks

– abann sunny
Jan 15 at 21:01

add a comment |

This will probably never see the light of day... but here it is anyway.

Replace bracket syntax with .

Split on . character

Remove blank strings

Find the path (otherwise undefined)

// "one liner" (ES6)



const deep_value = (obj, path) => 

  path

    .replace(/[|].?/g, '.')

    .split('.')

    .filter(s => s)

    .reduce((acc, val) => acc && acc[val], obj);

    

// ... and that's it.



var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }

        // ...

    ]

};



console.log(deep_value(someObject, "part1.name"));               // Part 1

console.log(deep_value(someObject, "part2.qty"));                // 60

console.log(deep_value(someObject, "part3[0].name"));            // Part 3A

edited Nov 10 '18 at 13:24

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

1

It did see the light of the day!! thanks

– abann sunny
Jan 15 at 21:01

add a comment |

This will probably never see the light of day... but here it is anyway.

Replace bracket syntax with .

Split on . character

Remove blank strings

Find the path (otherwise undefined)

// "one liner" (ES6)



const deep_value = (obj, path) => 

  path

    .replace(/[|].?/g, '.')

    .split('.')

    .filter(s => s)

    .reduce((acc, val) => acc && acc[val], obj);

    

// ... and that's it.



var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }

        // ...

    ]

};



console.log(deep_value(someObject, "part1.name"));               // Part 1

console.log(deep_value(someObject, "part2.qty"));                // 60

console.log(deep_value(someObject, "part3[0].name"));            // Part 3A

edited Nov 10 '18 at 13:24

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

This will probably never see the light of day... but here it is anyway.

Replace bracket syntax with .

Split on . character

Remove blank strings

Find the path (otherwise undefined)

// "one liner" (ES6)



const deep_value = (obj, path) => 

  path

    .replace(/[|].?/g, '.')

    .split('.')

    .filter(s => s)

    .reduce((acc, val) => acc && acc[val], obj);

    

// ... and that's it.



var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }

        // ...

    ]

};



console.log(deep_value(someObject, "part1.name"));               // Part 1

console.log(deep_value(someObject, "part2.qty"));                // 60

console.log(deep_value(someObject, "part3[0].name"));            // Part 3A

// "one liner" (ES6)



const deep_value = (obj, path) => 

  path

    .replace(/[|].?/g, '.')

    .split('.')

    .filter(s => s)

    .reduce((acc, val) => acc && acc[val], obj);

    

// ... and that's it.



var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }

        // ...

    ]

};



console.log(deep_value(someObject, "part1.name"));               // Part 1

console.log(deep_value(someObject, "part2.qty"));                // 60

console.log(deep_value(someObject, "part3[0].name"));            // Part 3A

// "one liner" (ES6)



const deep_value = (obj, path) => 

  path

    .replace(/[|].?/g, '.')

    .split('.')

    .filter(s => s)

    .reduce((acc, val) => acc && acc[val], obj);

    

// ... and that's it.



var someObject = {

    'part1' : {

        'name': 'Part 1',

        'size': '20',

        'qty' : '50'

    },

    'part2' : {

        'name': 'Part 2',

        'size': '15',

        'qty' : '60'

    },

    'part3' : [

        {

            'name': 'Part 3A',

            'size': '10',

            'qty' : '20'

        }

        // ...

    ]

};



console.log(deep_value(someObject, "part1.name"));               // Part 1

console.log(deep_value(someObject, "part2.qty"));                // 60

console.log(deep_value(someObject, "part3[0].name"));            // Part 3A

edited Nov 10 '18 at 13:24

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

edited Nov 10 '18 at 13:24

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

answered Jun 26 '18 at 18:16

Nick Grealy

10.7k65778

1

It did see the light of the day!! thanks

– abann sunny
Jan 15 at 21:01

add a comment |

1

It did see the light of the day!! thanks

– abann sunny
Jan 15 at 21:01

It did see the light of the day!! thanks

– abann sunny
Jan 15 at 21:01

add a comment |

I think you are asking for this:

var part1name = someObject.part1.name;

var part2quantity = someObject.part2.qty;

var part3name1 =  someObject.part3[0].name;

You could be asking for this:

var part1name = someObject["part1"]["name"];

var part2quantity = someObject["part2"]["qty"];

var part3name1 =  someObject["part3"][0]["name"];

Both of which will work

Or maybe you are asking for this

var partName = "part1";

var nameStr = "name";



var part1name = someObject[partName][nameStr];

Finally you could be asking for this

var partName = "part1.name";



var partBits = partName.split(".");



var part1name = someObject[partBits[0]][partBits[1]];

edited Jun 27 '11 at 20:46

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

I think OP's asking for the last solution. However, strings don't have Split method, but rather split.

– duri
Jun 27 '11 at 10:37

Actualy I was asking the last one. The partName variable is filled with string indicating the key-structure to value. Your solution seems makes sense. However I may need to modify for extended depth in the data, like 4-5 level and more. And I am wondering if I can treat the array and object uniformly with this?

– Komaruloh
Jun 27 '11 at 10:38

add a comment |

I think you are asking for this:

var part1name = someObject.part1.name;

var part2quantity = someObject.part2.qty;

var part3name1 =  someObject.part3[0].name;

You could be asking for this:

var part1name = someObject["part1"]["name"];

var part2quantity = someObject["part2"]["qty"];

var part3name1 =  someObject["part3"][0]["name"];

Both of which will work

Or maybe you are asking for this

var partName = "part1";

var nameStr = "name";



var part1name = someObject[partName][nameStr];

Finally you could be asking for this

var partName = "part1.name";



var partBits = partName.split(".");



var part1name = someObject[partBits[0]][partBits[1]];

edited Jun 27 '11 at 20:46

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

I think OP's asking for the last solution. However, strings don't have Split method, but rather split.

– duri
Jun 27 '11 at 10:37

Actualy I was asking the last one. The partName variable is filled with string indicating the key-structure to value. Your solution seems makes sense. However I may need to modify for extended depth in the data, like 4-5 level and more. And I am wondering if I can treat the array and object uniformly with this?

– Komaruloh
Jun 27 '11 at 10:38

add a comment |

I think you are asking for this:

var part1name = someObject.part1.name;

var part2quantity = someObject.part2.qty;

var part3name1 =  someObject.part3[0].name;

You could be asking for this:

var part1name = someObject["part1"]["name"];

var part2quantity = someObject["part2"]["qty"];

var part3name1 =  someObject["part3"][0]["name"];

Both of which will work

Or maybe you are asking for this

var partName = "part1";

var nameStr = "name";



var part1name = someObject[partName][nameStr];

Finally you could be asking for this

var partName = "part1.name";



var partBits = partName.split(".");



var part1name = someObject[partBits[0]][partBits[1]];

edited Jun 27 '11 at 20:46

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

I think you are asking for this:

var part1name = someObject.part1.name;

var part2quantity = someObject.part2.qty;

var part3name1 =  someObject.part3[0].name;

You could be asking for this:

var part1name = someObject["part1"]["name"];

var part2quantity = someObject["part2"]["qty"];

var part3name1 =  someObject["part3"][0]["name"];

Both of which will work

Or maybe you are asking for this

var partName = "part1";

var nameStr = "name";



var part1name = someObject[partName][nameStr];

Finally you could be asking for this

var partName = "part1.name";



var partBits = partName.split(".");



var part1name = someObject[partBits[0]][partBits[1]];

edited Jun 27 '11 at 20:46

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

edited Jun 27 '11 at 20:46

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

answered Jun 27 '11 at 10:28

Hogan

54.8k865102

I think OP's asking for the last solution. However, strings don't have Split method, but rather split.

– duri
Jun 27 '11 at 10:37

Actualy I was asking the last one. The partName variable is filled with string indicating the key-structure to value. Your solution seems makes sense. However I may need to modify for extended depth in the data, like 4-5 level and more. And I am wondering if I can treat the array and object uniformly with this?

– Komaruloh
Jun 27 '11 at 10:38

add a comment |

I think OP's asking for the last solution. However, strings don't have Split method, but rather split.

– duri
Jun 27 '11 at 10:37

Actualy I was asking the last one. The partName variable is filled with string indicating the key-structure to value. Your solution seems makes sense. However I may need to modify for extended depth in the data, like 4-5 level and more. And I am wondering if I can treat the array and object uniformly with this?

– Komaruloh
Jun 27 '11 at 10:38

I think OP's asking for the last solution. However, strings don't have Split method, but rather split.

– duri
Jun 27 '11 at 10:37

Actualy I was asking the last one. The partName variable is filled with string indicating the key-structure to value. Your solution seems makes sense. However I may need to modify for extended depth in the data, like 4-5 level and more. And I am wondering if I can treat the array and object uniformly with this?

– Komaruloh
Jun 27 '11 at 10:38

add a comment |

$scope.resolve = function( path, obj ) {

    return path.split('.').reduce( function( prev, curr ) {

        return prev[curr];

    }, obj || this );

}

Just place this function in your root controller and use it any child scope like this:

$scope.resolve( 'path.to.any.object.in.scope')

answered Feb 26 '15 at 12:22

nesinervink

12818

add a comment |

$scope.resolve = function( path, obj ) {

    return path.split('.').reduce( function( prev, curr ) {

        return prev[curr];

    }, obj || this );

}

Just place this function in your root controller and use it any child scope like this:

$scope.resolve( 'path.to.any.object.in.scope')

answered Feb 26 '15 at 12:22

nesinervink

12818

add a comment |

$scope.resolve = function( path, obj ) {

    return path.split('.').reduce( function( prev, curr ) {

        return prev[curr];

    }, obj || this );

}

Just place this function in your root controller and use it any child scope like this:

$scope.resolve( 'path.to.any.object.in.scope')

answered Feb 26 '15 at 12:22

nesinervink

12818

$scope.resolve = function( path, obj ) {

    return path.split('.').reduce( function( prev, curr ) {

        return prev[curr];

    }, obj || this );

}

Just place this function in your root controller and use it any child scope like this:

$scope.resolve( 'path.to.any.object.in.scope')

answered Feb 26 '15 at 12:22

nesinervink

12818

answered Feb 26 '15 at 12:22

nesinervink

12818

answered Feb 26 '15 at 12:22

nesinervink

12818

answered Feb 26 '15 at 12:22

nesinervink

12818

add a comment |

It's a one liner with lodash.

const deep = { l1: { l2: { l3: "Hello" } } };

const prop = "l1.l2.l3";

const val = _.reduce(prop.split('.'), function(result, value) { return result ? result[value] : undefined; }, deep);

// val === "Hello"

Or even better...

const val = _.get(deep, prop);

Or ES6 version w/ reduce...

const val = prop.split('.').reduce((r, val) => { return r ? r[val] : undefined; }, deep);

Plunkr

edited Nov 18 '17 at 0:50

answered Dec 8 '16 at 16:19

James

2,4711615

add a comment |

It's a one liner with lodash.

const deep = { l1: { l2: { l3: "Hello" } } };

const prop = "l1.l2.l3";

const val = _.reduce(prop.split('.'), function(result, value) { return result ? result[value] : undefined; }, deep);

// val === "Hello"

Or even better...

const val = _.get(deep, prop);

Or ES6 version w/ reduce...

const val = prop.split('.').reduce((r, val) => { return r ? r[val] : undefined; }, deep);

Plunkr

edited Nov 18 '17 at 0:50

answered Dec 8 '16 at 16:19

James

2,4711615

add a comment |

It's a one liner with lodash.

const deep = { l1: { l2: { l3: "Hello" } } };

const prop = "l1.l2.l3";

const val = _.reduce(prop.split('.'), function(result, value) { return result ? result[value] : undefined; }, deep);

// val === "Hello"

Or even better...

const val = _.get(deep, prop);

Or ES6 version w/ reduce...

const val = prop.split('.').reduce((r, val) => { return r ? r[val] : undefined; }, deep);

Plunkr

edited Nov 18 '17 at 0:50

answered Dec 8 '16 at 16:19

James

2,4711615

It's a one liner with lodash.

const deep = { l1: { l2: { l3: "Hello" } } };

const prop = "l1.l2.l3";

const val = _.reduce(prop.split('.'), function(result, value) { return result ? result[value] : undefined; }, deep);

// val === "Hello"

Or even better...

const val = _.get(deep, prop);

Or ES6 version w/ reduce...

const val = prop.split('.').reduce((r, val) => { return r ? r[val] : undefined; }, deep);

Plunkr

edited Nov 18 '17 at 0:50

answered Dec 8 '16 at 16:19

James

2,4711615

edited Nov 18 '17 at 0:50

answered Dec 8 '16 at 16:19

James

2,4711615

answered Dec 8 '16 at 16:19

James

2,4711615

answered Dec 8 '16 at 16:19

James

2,4711615

add a comment |

You can use dot notation, brackets, number indices, string number properties, and keys with non-word characters. Simple usage below:

> var jsocrud = require('jsocrud');



...



// Get (Read) ---

> var obj = {

>     foo: [

>         {

>             'key w/ non-word chars': 'bar'

>         }

>     ]

> };

undefined



> jsocrud.get(obj, '.foo[0]["key w/ non-word chars"]');

'bar'

https://www.npmjs.com/package/jsocrud

https://github.com/vertical-knowledge/jsocrud

edited Apr 25 '15 at 1:32

answered Apr 25 '15 at 1:08

Kyle

314

add a comment |

You can use dot notation, brackets, number indices, string number properties, and keys with non-word characters. Simple usage below:

> var jsocrud = require('jsocrud');



...



// Get (Read) ---

> var obj = {

>     foo: [

>         {

>             'key w/ non-word chars': 'bar'

>         }

>     ]

> };

undefined



> jsocrud.get(obj, '.foo[0]["key w/ non-word chars"]');

'bar'

https://www.npmjs.com/package/jsocrud

https://github.com/vertical-knowledge/jsocrud

edited Apr 25 '15 at 1:32

answered Apr 25 '15 at 1:08

Kyle

314

add a comment |

You can use dot notation, brackets, number indices, string number properties, and keys with non-word characters. Simple usage below:

> var jsocrud = require('jsocrud');



...



// Get (Read) ---

> var obj = {

>     foo: [

>         {

>             'key w/ non-word chars': 'bar'

>         }

>     ]

> };

undefined



> jsocrud.get(obj, '.foo[0]["key w/ non-word chars"]');

'bar'

https://www.npmjs.com/package/jsocrud

https://github.com/vertical-knowledge/jsocrud

edited Apr 25 '15 at 1:32

answered Apr 25 '15 at 1:08

Kyle

314

You can use dot notation, brackets, number indices, string number properties, and keys with non-word characters. Simple usage below:

> var jsocrud = require('jsocrud');



...



// Get (Read) ---

> var obj = {

>     foo: [

>         {

>             'key w/ non-word chars': 'bar'

>         }

>     ]

> };

undefined



> jsocrud.get(obj, '.foo[0]["key w/ non-word chars"]');

'bar'

https://www.npmjs.com/package/jsocrud

https://github.com/vertical-knowledge/jsocrud

edited Apr 25 '15 at 1:32

answered Apr 25 '15 at 1:08

Kyle

314

edited Apr 25 '15 at 1:32

answered Apr 25 '15 at 1:08

Kyle

314

answered Apr 25 '15 at 1:08

Kyle

314

answered Apr 25 '15 at 1:08

Kyle

314

add a comment |

Simple function, allowing for either a string or array path.

function get(obj, path) {

  if(typeof path === 'string') path = path.split('.');



  if(path.length === 0) return obj;

  return get(obj[path[0]], path.slice(1));

}



const obj = {a: {b: {c: 'foo'}}};



console.log(get(obj, 'a.b.c')); //foo

console.log(get(obj, ['a', 'b', 'c'])); //foo

edited Dec 26 '16 at 14:42

answered Dec 26 '16 at 4:51

Ben

1,4171317

If you're going to post code as an answer, please explain why the code answers the question.

– Tieson T.
Dec 26 '16 at 5:44

add a comment |

Simple function, allowing for either a string or array path.

function get(obj, path) {

  if(typeof path === 'string') path = path.split('.');



  if(path.length === 0) return obj;

  return get(obj[path[0]], path.slice(1));

}



const obj = {a: {b: {c: 'foo'}}};



console.log(get(obj, 'a.b.c')); //foo

console.log(get(obj, ['a', 'b', 'c'])); //foo

edited Dec 26 '16 at 14:42

answered Dec 26 '16 at 4:51

Ben

1,4171317

If you're going to post code as an answer, please explain why the code answers the question.

– Tieson T.
Dec 26 '16 at 5:44

add a comment |

Simple function, allowing for either a string or array path.

function get(obj, path) {

  if(typeof path === 'string') path = path.split('.');



  if(path.length === 0) return obj;

  return get(obj[path[0]], path.slice(1));

}



const obj = {a: {b: {c: 'foo'}}};



console.log(get(obj, 'a.b.c')); //foo

console.log(get(obj, ['a', 'b', 'c'])); //foo

edited Dec 26 '16 at 14:42

answered Dec 26 '16 at 4:51

Ben

1,4171317

Simple function, allowing for either a string or array path.

function get(obj, path) {

  if(typeof path === 'string') path = path.split('.');



  if(path.length === 0) return obj;

  return get(obj[path[0]], path.slice(1));

}



const obj = {a: {b: {c: 'foo'}}};



console.log(get(obj, 'a.b.c')); //foo

console.log(get(obj, ['a', 'b', 'c'])); //foo

edited Dec 26 '16 at 14:42

answered Dec 26 '16 at 4:51

Ben

1,4171317

edited Dec 26 '16 at 14:42

answered Dec 26 '16 at 4:51

Ben

1,4171317

answered Dec 26 '16 at 4:51

Ben

1,4171317

answered Dec 26 '16 at 4:51

Ben

1,4171317

If you're going to post code as an answer, please explain why the code answers the question.

– Tieson T.
Dec 26 '16 at 5:44

add a comment |

If you're going to post code as an answer, please explain why the code answers the question.

– Tieson T.
Dec 26 '16 at 5:44

If you're going to post code as an answer, please explain why the code answers the question.

– Tieson T.
Dec 26 '16 at 5:44

add a comment |

Cannot read property 'foo' of undefined error

Access Nested Objects Using Array Reduce

Let's take this example structure

const user = {

    id: 101,

    email: 'jack@dev.com',

    personalInfo: {

        name: 'Jack',

        address: [{

            line1: 'westwish st',

            line2: 'washmasher',

            city: 'wallas',

            state: 'WX'

        }]

    }

}

To be able to access nested arrays, you can write your own array reduce util.

const getNestedObject = (nestedObj, pathArr) => {

    return pathArr.reduce((obj, key) =>

        (obj && obj[key] !== 'undefined') ? obj[key] : undefined, nestedObj);

}



// pass in your object structure as array elements

const name = getNestedObject(user, ['personalInfo', 'name']);



// to access nested array, just pass in array index as an element the path array.

const city = getNestedObject(user, ['personalInfo', 'address', 0, 'city']);

// this will return the city from the first address item.

There is also an excellent type handling minimal library typy that does all this for you.

With typy, your code will look like this

const city = t(user, 'personalInfo.address[0].city').safeObject;

Disclaimer: I am the author of this package.

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

add a comment |

Cannot read property 'foo' of undefined error

Access Nested Objects Using Array Reduce

Let's take this example structure

const user = {

    id: 101,

    email: 'jack@dev.com',

    personalInfo: {

        name: 'Jack',

        address: [{

            line1: 'westwish st',

            line2: 'washmasher',

            city: 'wallas',

            state: 'WX'

        }]

    }

}

To be able to access nested arrays, you can write your own array reduce util.

const getNestedObject = (nestedObj, pathArr) => {

    return pathArr.reduce((obj, key) =>

        (obj && obj[key] !== 'undefined') ? obj[key] : undefined, nestedObj);

}



// pass in your object structure as array elements

const name = getNestedObject(user, ['personalInfo', 'name']);



// to access nested array, just pass in array index as an element the path array.

const city = getNestedObject(user, ['personalInfo', 'address', 0, 'city']);

// this will return the city from the first address item.

There is also an excellent type handling minimal library typy that does all this for you.

With typy, your code will look like this

const city = t(user, 'personalInfo.address[0].city').safeObject;

Disclaimer: I am the author of this package.

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

add a comment |

Cannot read property 'foo' of undefined error

Access Nested Objects Using Array Reduce

Let's take this example structure

const user = {

    id: 101,

    email: 'jack@dev.com',

    personalInfo: {

        name: 'Jack',

        address: [{

            line1: 'westwish st',

            line2: 'washmasher',

            city: 'wallas',

            state: 'WX'

        }]

    }

}

To be able to access nested arrays, you can write your own array reduce util.

const getNestedObject = (nestedObj, pathArr) => {

    return pathArr.reduce((obj, key) =>

        (obj && obj[key] !== 'undefined') ? obj[key] : undefined, nestedObj);

}



// pass in your object structure as array elements

const name = getNestedObject(user, ['personalInfo', 'name']);



// to access nested array, just pass in array index as an element the path array.

const city = getNestedObject(user, ['personalInfo', 'address', 0, 'city']);

// this will return the city from the first address item.

There is also an excellent type handling minimal library typy that does all this for you.

With typy, your code will look like this

const city = t(user, 'personalInfo.address[0].city').safeObject;

Disclaimer: I am the author of this package.

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

Cannot read property 'foo' of undefined error

Access Nested Objects Using Array Reduce

Let's take this example structure

const user = {

    id: 101,

    email: 'jack@dev.com',

    personalInfo: {

        name: 'Jack',

        address: [{

            line1: 'westwish st',

            line2: 'washmasher',

            city: 'wallas',

            state: 'WX'

        }]

    }

}

To be able to access nested arrays, you can write your own array reduce util.

const getNestedObject = (nestedObj, pathArr) => {

    return pathArr.reduce((obj, key) =>

        (obj && obj[key] !== 'undefined') ? obj[key] : undefined, nestedObj);

}



// pass in your object structure as array elements

const name = getNestedObject(user, ['personalInfo', 'name']);



// to access nested array, just pass in array index as an element the path array.

const city = getNestedObject(user, ['personalInfo', 'address', 0, 'city']);

// this will return the city from the first address item.

There is also an excellent type handling minimal library typy that does all this for you.

With typy, your code will look like this

const city = t(user, 'personalInfo.address[0].city').safeObject;

Disclaimer: I am the author of this package.

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

answered Jul 8 '18 at 13:01

Dinesh Pandiyan

2,495925

add a comment |

There is an npm module now for doing this: https://github.com/erictrinh/safe-access

Example usage:

var access = require('safe-access');

access(very, 'nested.property.and.array[0]');

answered Jun 13 '14 at 18:56

caleb

1,3751420

add a comment |

There is an npm module now for doing this: https://github.com/erictrinh/safe-access

Example usage:

var access = require('safe-access');

access(very, 'nested.property.and.array[0]');

answered Jun 13 '14 at 18:56

caleb

1,3751420

add a comment |

There is an npm module now for doing this: https://github.com/erictrinh/safe-access

Example usage:

var access = require('safe-access');

access(very, 'nested.property.and.array[0]');

answered Jun 13 '14 at 18:56

caleb

1,3751420

There is an npm module now for doing this: https://github.com/erictrinh/safe-access

Example usage:

var access = require('safe-access');

access(very, 'nested.property.and.array[0]');

answered Jun 13 '14 at 18:56

caleb

1,3751420

answered Jun 13 '14 at 18:56

caleb

1,3751420

answered Jun 13 '14 at 18:56

caleb

1,3751420

answered Jun 13 '14 at 18:56

caleb

1,3751420

add a comment |

/**

 * Access a deep value inside a object 

 * Works by passing a path like "foo.bar", also works with nested arrays like "foo[0][1].baz"

 * @author Victor B. https://gist.github.com/victornpb/4c7882c1b9d36292308e

 * Unit tests: http://jsfiddle.net/Victornpb/0u1qygrh/

 */

function getDeepVal(obj, path) {

    if (typeof obj === "undefined" || obj === null) return;

    path = path.split(/[.[]"']{1,2}/);

    for (var i = 0, l = path.length; i < l; i++) {

        if (path[i] === "") continue;

        obj = obj[path[i]];

        if (typeof obj === "undefined" || obj === null) return;

    }

    return obj;

}

Works with

getDeepVal(obj,'foo.bar')

getDeepVal(obj,'foo.1.bar')

getDeepVal(obj,'foo[0].baz')

getDeepVal(obj,'foo[1][2]')

getDeepVal(obj,"foo['bar'].baz")

getDeepVal(obj,"foo['bar']['baz']")

getDeepVal(obj,"foo.bar.0.baz[1]['2']['w'].aaa["f"].bb")

edited Sep 29 '16 at 19:51

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

add a comment |

/**

 * Access a deep value inside a object 

 * Works by passing a path like "foo.bar", also works with nested arrays like "foo[0][1].baz"

 * @author Victor B. https://gist.github.com/victornpb/4c7882c1b9d36292308e

 * Unit tests: http://jsfiddle.net/Victornpb/0u1qygrh/

 */

function getDeepVal(obj, path) {

    if (typeof obj === "undefined" || obj === null) return;

    path = path.split(/[.[]"']{1,2}/);

    for (var i = 0, l = path.length; i < l; i++) {

        if (path[i] === "") continue;

        obj = obj[path[i]];

        if (typeof obj === "undefined" || obj === null) return;

    }

    return obj;

}

Works with

getDeepVal(obj,'foo.bar')

getDeepVal(obj,'foo.1.bar')

getDeepVal(obj,'foo[0].baz')

getDeepVal(obj,'foo[1][2]')

getDeepVal(obj,"foo['bar'].baz")

getDeepVal(obj,"foo['bar']['baz']")

getDeepVal(obj,"foo.bar.0.baz[1]['2']['w'].aaa["f"].bb")

edited Sep 29 '16 at 19:51

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

add a comment |

/**

 * Access a deep value inside a object 

 * Works by passing a path like "foo.bar", also works with nested arrays like "foo[0][1].baz"

 * @author Victor B. https://gist.github.com/victornpb/4c7882c1b9d36292308e

 * Unit tests: http://jsfiddle.net/Victornpb/0u1qygrh/

 */

function getDeepVal(obj, path) {

    if (typeof obj === "undefined" || obj === null) return;

    path = path.split(/[.[]"']{1,2}/);

    for (var i = 0, l = path.length; i < l; i++) {

        if (path[i] === "") continue;

        obj = obj[path[i]];

        if (typeof obj === "undefined" || obj === null) return;

    }

    return obj;

}

Works with

getDeepVal(obj,'foo.bar')

getDeepVal(obj,'foo.1.bar')

getDeepVal(obj,'foo[0].baz')

getDeepVal(obj,'foo[1][2]')

getDeepVal(obj,"foo['bar'].baz")

getDeepVal(obj,"foo['bar']['baz']")

getDeepVal(obj,"foo.bar.0.baz[1]['2']['w'].aaa["f"].bb")

edited Sep 29 '16 at 19:51

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

/**

 * Access a deep value inside a object 

 * Works by passing a path like "foo.bar", also works with nested arrays like "foo[0][1].baz"

 * @author Victor B. https://gist.github.com/victornpb/4c7882c1b9d36292308e

 * Unit tests: http://jsfiddle.net/Victornpb/0u1qygrh/

 */

function getDeepVal(obj, path) {

    if (typeof obj === "undefined" || obj === null) return;

    path = path.split(/[.[]"']{1,2}/);

    for (var i = 0, l = path.length; i < l; i++) {

        if (path[i] === "") continue;

        obj = obj[path[i]];

        if (typeof obj === "undefined" || obj === null) return;

    }

    return obj;

}

Works with

getDeepVal(obj,'foo.bar')

getDeepVal(obj,'foo.1.bar')

getDeepVal(obj,'foo[0].baz')

getDeepVal(obj,'foo[1][2]')

getDeepVal(obj,"foo['bar'].baz")

getDeepVal(obj,"foo['bar']['baz']")

getDeepVal(obj,"foo.bar.0.baz[1]['2']['w'].aaa["f"].bb")

edited Sep 29 '16 at 19:51

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

edited Sep 29 '16 at 19:51

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

answered Mar 1 '16 at 17:05

Vitim.us

9,81696280

add a comment |

While reduce is good, I am surprised no one used forEach:

function valueForKeyPath(obj, path){

        const keys = path.split('.');

        keys.forEach((key)=> obj = obj[key]);

        return obj;

    };

Test

edited Dec 15 '17 at 14:03

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

You are not even checking if obj[key] actually exists. It's unreliable.

– Carles Alcolea
Jul 22 '18 at 4:08

@CarlesAlcolea by default js will neither check if the key of an object exists: a.b.c will raise an exception if there is no property b in your object. If you need something silently dismissing the wrong keypath (which I do not recommend), you can still replace the forEach with this one keys.forEach((key)=> obj = (obj||{})[key]);

– Flavien Volken
Jul 23 '18 at 7:57

I run through it an object that was missing a curly brace, my bad :)

– Carles Alcolea
Jul 28 '18 at 23:59

add a comment |

While reduce is good, I am surprised no one used forEach:

function valueForKeyPath(obj, path){

        const keys = path.split('.');

        keys.forEach((key)=> obj = obj[key]);

        return obj;

    };

Test

edited Dec 15 '17 at 14:03

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

You are not even checking if obj[key] actually exists. It's unreliable.

– Carles Alcolea
Jul 22 '18 at 4:08

@CarlesAlcolea by default js will neither check if the key of an object exists: a.b.c will raise an exception if there is no property b in your object. If you need something silently dismissing the wrong keypath (which I do not recommend), you can still replace the forEach with this one keys.forEach((key)=> obj = (obj||{})[key]);

– Flavien Volken
Jul 23 '18 at 7:57

I run through it an object that was missing a curly brace, my bad :)

– Carles Alcolea
Jul 28 '18 at 23:59

add a comment |

While reduce is good, I am surprised no one used forEach:

function valueForKeyPath(obj, path){

        const keys = path.split('.');

        keys.forEach((key)=> obj = obj[key]);

        return obj;

    };

Test

edited Dec 15 '17 at 14:03

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

While reduce is good, I am surprised no one used forEach:

function valueForKeyPath(obj, path){

        const keys = path.split('.');

        keys.forEach((key)=> obj = obj[key]);

        return obj;

    };

Test

edited Dec 15 '17 at 14:03

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

edited Dec 15 '17 at 14:03

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

answered Dec 15 '17 at 13:54

Flavien Volken

9,41765575

You are not even checking if obj[key] actually exists. It's unreliable.

– Carles Alcolea
Jul 22 '18 at 4:08

@CarlesAlcolea by default js will neither check if the key of an object exists: a.b.c will raise an exception if there is no property b in your object. If you need something silently dismissing the wrong keypath (which I do not recommend), you can still replace the forEach with this one keys.forEach((key)=> obj = (obj||{})[key]);

– Flavien Volken
Jul 23 '18 at 7:57

I run through it an object that was missing a curly brace, my bad :)

– Carles Alcolea
Jul 28 '18 at 23:59

add a comment |

You are not even checking if obj[key] actually exists. It's unreliable.

– Carles Alcolea
Jul 22 '18 at 4:08

@CarlesAlcolea by default js will neither check if the key of an object exists: a.b.c will raise an exception if there is no property b in your object. If you need something silently dismissing the wrong keypath (which I do not recommend), you can still replace the forEach with this one keys.forEach((key)=> obj = (obj||{})[key]);

– Flavien Volken
Jul 23 '18 at 7:57

I run through it an object that was missing a curly brace, my bad :)

– Carles Alcolea
Jul 28 '18 at 23:59

You are not even checking if obj[key] actually exists. It's unreliable.

– Carles Alcolea
Jul 22 '18 at 4:08

@CarlesAlcolea by default js will neither check if the key of an object exists: a.b.c will raise an exception if there is no property b in your object. If you need something silently dismissing the wrong keypath (which I do not recommend), you can still replace the forEach with this one keys.forEach((key)=> obj = (obj||{})[key]);

– Flavien Volken
Jul 23 '18 at 7:57

I run through it an object that was missing a curly brace, my bad :)

– Carles Alcolea
Jul 28 '18 at 23:59

add a comment |

If you need to access different nested key without knowing it at coding time (it will be trivial to address them) you can use the array notation accessor:

var part1name = someObject['part1']['name'];

var part2quantity = someObject['part2']['qty'];

var part3name1 =  someObject['part3'][0]['name'];

They are equivalent to the dot notation accessor and may vary at runtime, for example:

var part = 'part1';

var property = 'name';



var part1name = someObject[part][property];

is equivalent to

var part1name = someObject['part1']['name'];

var part1name = someObject.part1.name;

I hope this address your question...

EDIT

I won't use a string to mantain a sort of xpath query to access an object value.
As you have to call a function to parse the query and retrieve the value I would follow another path (not :

var part1name = function(){ return this.part1.name; }

var part2quantity = function() { return this['part2']['qty']; }

var part3name1 =  function() { return this.part3[0]['name'];}



// usage: part1name.apply(someObject);

or, if you are uneasy with the apply method

var part1name = function(obj){ return obj.part1.name; }

var part2quantity = function(obj) { return obj['part2']['qty']; }

var part3name1 =  function(obj) { return obj.part3[0]['name'];}



// usage: part1name(someObject);

The functions are shorter, clearer, the interpreter check them for you for syntax errors and so on.

By the way, I feel that a simple assignment made at right time will be sufficent...

edited Jun 27 '11 at 11:35

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

Interesting. But in my case, the someObject is initialize yet when I assign value to part1name. I only know the structure. That is why I use string to describe the structure. And hoping to be able to use it to query my data from someObject. Thanks for sharing your thought. :)

– Komaruloh
Jun 27 '11 at 10:47

@Komaruloh : I think you would write that the object is NOT initialized yet when you create your variables. By the way I don't get the point, why can't you do the assignment at appropriate time?

– Eineki
Jun 27 '11 at 11:24

Sorry about not mentioning that someObject is not initialized yet. As for the reason, someObject is fetch via web service. And I want to have an array of header which consist of part1name, part2qty, etc. So that I could just loop through the header array and get the value I wanted based on part1name value as the 'key'/path to someObject.

– Komaruloh
Jun 27 '11 at 11:47

add a comment |

If you need to access different nested key without knowing it at coding time (it will be trivial to address them) you can use the array notation accessor:

var part1name = someObject['part1']['name'];

var part2quantity = someObject['part2']['qty'];

var part3name1 =  someObject['part3'][0]['name'];

They are equivalent to the dot notation accessor and may vary at runtime, for example:

var part = 'part1';

var property = 'name';



var part1name = someObject[part][property];

is equivalent to

var part1name = someObject['part1']['name'];

var part1name = someObject.part1.name;

I hope this address your question...

EDIT

I won't use a string to mantain a sort of xpath query to access an object value.
As you have to call a function to parse the query and retrieve the value I would follow another path (not :

var part1name = function(){ return this.part1.name; }

var part2quantity = function() { return this['part2']['qty']; }

var part3name1 =  function() { return this.part3[0]['name'];}



// usage: part1name.apply(someObject);

or, if you are uneasy with the apply method

var part1name = function(obj){ return obj.part1.name; }

var part2quantity = function(obj) { return obj['part2']['qty']; }

var part3name1 =  function(obj) { return obj.part3[0]['name'];}



// usage: part1name(someObject);

The functions are shorter, clearer, the interpreter check them for you for syntax errors and so on.

By the way, I feel that a simple assignment made at right time will be sufficent...

edited Jun 27 '11 at 11:35

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

Interesting. But in my case, the someObject is initialize yet when I assign value to part1name. I only know the structure. That is why I use string to describe the structure. And hoping to be able to use it to query my data from someObject. Thanks for sharing your thought. :)

– Komaruloh
Jun 27 '11 at 10:47

@Komaruloh : I think you would write that the object is NOT initialized yet when you create your variables. By the way I don't get the point, why can't you do the assignment at appropriate time?

– Eineki
Jun 27 '11 at 11:24

Sorry about not mentioning that someObject is not initialized yet. As for the reason, someObject is fetch via web service. And I want to have an array of header which consist of part1name, part2qty, etc. So that I could just loop through the header array and get the value I wanted based on part1name value as the 'key'/path to someObject.

– Komaruloh
Jun 27 '11 at 11:47

add a comment |

If you need to access different nested key without knowing it at coding time (it will be trivial to address them) you can use the array notation accessor:

var part1name = someObject['part1']['name'];

var part2quantity = someObject['part2']['qty'];

var part3name1 =  someObject['part3'][0]['name'];

They are equivalent to the dot notation accessor and may vary at runtime, for example:

var part = 'part1';

var property = 'name';



var part1name = someObject[part][property];

is equivalent to

var part1name = someObject['part1']['name'];

var part1name = someObject.part1.name;

I hope this address your question...

EDIT

I won't use a string to mantain a sort of xpath query to access an object value.
As you have to call a function to parse the query and retrieve the value I would follow another path (not :

var part1name = function(){ return this.part1.name; }

var part2quantity = function() { return this['part2']['qty']; }

var part3name1 =  function() { return this.part3[0]['name'];}



// usage: part1name.apply(someObject);

or, if you are uneasy with the apply method

var part1name = function(obj){ return obj.part1.name; }

var part2quantity = function(obj) { return obj['part2']['qty']; }

var part3name1 =  function(obj) { return obj.part3[0]['name'];}



// usage: part1name(someObject);

The functions are shorter, clearer, the interpreter check them for you for syntax errors and so on.

By the way, I feel that a simple assignment made at right time will be sufficent...

edited Jun 27 '11 at 11:35

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

If you need to access different nested key without knowing it at coding time (it will be trivial to address them) you can use the array notation accessor:

var part1name = someObject['part1']['name'];

var part2quantity = someObject['part2']['qty'];

var part3name1 =  someObject['part3'][0]['name'];

They are equivalent to the dot notation accessor and may vary at runtime, for example:

var part = 'part1';

var property = 'name';



var part1name = someObject[part][property];

is equivalent to

var part1name = someObject['part1']['name'];

var part1name = someObject.part1.name;

I hope this address your question...

EDIT

I won't use a string to mantain a sort of xpath query to access an object value.
As you have to call a function to parse the query and retrieve the value I would follow another path (not :

var part1name = function(){ return this.part1.name; }

var part2quantity = function() { return this['part2']['qty']; }

var part3name1 =  function() { return this.part3[0]['name'];}



// usage: part1name.apply(someObject);

or, if you are uneasy with the apply method

var part1name = function(obj){ return obj.part1.name; }

var part2quantity = function(obj) { return obj['part2']['qty']; }

var part3name1 =  function(obj) { return obj.part3[0]['name'];}



// usage: part1name(someObject);

The functions are shorter, clearer, the interpreter check them for you for syntax errors and so on.

By the way, I feel that a simple assignment made at right time will be sufficent...

edited Jun 27 '11 at 11:35

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

edited Jun 27 '11 at 11:35

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

answered Jun 27 '11 at 10:36

Eineki

12.7k53751

Interesting. But in my case, the someObject is initialize yet when I assign value to part1name. I only know the structure. That is why I use string to describe the structure. And hoping to be able to use it to query my data from someObject. Thanks for sharing your thought. :)

– Komaruloh
Jun 27 '11 at 10:47

@Komaruloh : I think you would write that the object is NOT initialized yet when you create your variables. By the way I don't get the point, why can't you do the assignment at appropriate time?

– Eineki
Jun 27 '11 at 11:24

Sorry about not mentioning that someObject is not initialized yet. As for the reason, someObject is fetch via web service. And I want to have an array of header which consist of part1name, part2qty, etc. So that I could just loop through the header array and get the value I wanted based on part1name value as the 'key'/path to someObject.

– Komaruloh
Jun 27 '11 at 11:47

add a comment |

Interesting. But in my case, the someObject is initialize yet when I assign value to part1name. I only know the structure. That is why I use string to describe the structure. And hoping to be able to use it to query my data from someObject. Thanks for sharing your thought. :)

– Komaruloh
Jun 27 '11 at 10:47

@Komaruloh : I think you would write that the object is NOT initialized yet when you create your variables. By the way I don't get the point, why can't you do the assignment at appropriate time?

– Eineki
Jun 27 '11 at 11:24

Sorry about not mentioning that someObject is not initialized yet. As for the reason, someObject is fetch via web service. And I want to have an array of header which consist of part1name, part2qty, etc. So that I could just loop through the header array and get the value I wanted based on part1name value as the 'key'/path to someObject.

– Komaruloh
Jun 27 '11 at 11:47

Interesting. But in my case, the someObject is initialize yet when I assign value to part1name. I only know the structure. That is why I use string to describe the structure. And hoping to be able to use it to query my data from someObject. Thanks for sharing your thought. :)

– Komaruloh
Jun 27 '11 at 10:47

@Komaruloh : I think you would write that the object is NOT initialized yet when you create your variables. By the way I don't get the point, why can't you do the assignment at appropriate time?

– Eineki
Jun 27 '11 at 11:24

Sorry about not mentioning that someObject is not initialized yet. As for the reason, someObject is fetch via web service. And I want to have an array of header which consist of part1name, part2qty, etc. So that I could just loop through the header array and get the value I wanted based on part1name value as the 'key'/path to someObject.

– Komaruloh
Jun 27 '11 at 11:47

add a comment |

Just had the same question recently and successfully used https://npmjs.org/package/tea-properties which also set nested object/arrays :

get:

var o = {

  prop: {

    arr: [

      {foo: 'bar'}

    ]

  }

};



var properties = require('tea-properties');

var value = properties.get(o, 'prop.arr[0].foo');



assert(value, 'bar'); // true

set:

var o = {};



var properties = require('tea-properties');

properties.set(o, 'prop.arr[0].foo', 'bar');



assert(o.prop.arr[0].foo, 'bar'); // true

edited Nov 4 '13 at 0:41

answered Oct 25 '13 at 19:33

abernier

13.2k156693

"This module has been discontinued. Use chaijs/pathval."

– Patrick Fisher
Mar 18 '14 at 0:09

add a comment |

Just had the same question recently and successfully used https://npmjs.org/package/tea-properties which also set nested object/arrays :

get:

var o = {

  prop: {

    arr: [

      {foo: 'bar'}

    ]

  }

};



var properties = require('tea-properties');

var value = properties.get(o, 'prop.arr[0].foo');



assert(value, 'bar'); // true

set:

var o = {};



var properties = require('tea-properties');

properties.set(o, 'prop.arr[0].foo', 'bar');



assert(o.prop.arr[0].foo, 'bar'); // true

edited Nov 4 '13 at 0:41

answered Oct 25 '13 at 19:33

abernier

13.2k156693

"This module has been discontinued. Use chaijs/pathval."

– Patrick Fisher
Mar 18 '14 at 0:09

add a comment |

Just had the same question recently and successfully used https://npmjs.org/package/tea-properties which also set nested object/arrays :

get:

var o = {

  prop: {

    arr: [

      {foo: 'bar'}

    ]

  }

};



var properties = require('tea-properties');

var value = properties.get(o, 'prop.arr[0].foo');



assert(value, 'bar'); // true

set:

var o = {};



var properties = require('tea-properties');

properties.set(o, 'prop.arr[0].foo', 'bar');



assert(o.prop.arr[0].foo, 'bar'); // true

edited Nov 4 '13 at 0:41

answered Oct 25 '13 at 19:33

abernier

13.2k156693

Just had the same question recently and successfully used https://npmjs.org/package/tea-properties which also set nested object/arrays :

get:

var o = {

  prop: {

    arr: [

      {foo: 'bar'}

    ]

  }

};



var properties = require('tea-properties');

var value = properties.get(o, 'prop.arr[0].foo');



assert(value, 'bar'); // true

set:

var o = {};



var properties = require('tea-properties');

properties.set(o, 'prop.arr[0].foo', 'bar');



assert(o.prop.arr[0].foo, 'bar'); // true

edited Nov 4 '13 at 0:41

answered Oct 25 '13 at 19:33

abernier

13.2k156693

edited Nov 4 '13 at 0:41

answered Oct 25 '13 at 19:33

abernier

13.2k156693

answered Oct 25 '13 at 19:33

abernier

13.2k156693

answered Oct 25 '13 at 19:33

abernier

13.2k156693

"This module has been discontinued. Use chaijs/pathval."

– Patrick Fisher
Mar 18 '14 at 0:09

add a comment |

"This module has been discontinued. Use chaijs/pathval."

– Patrick Fisher
Mar 18 '14 at 0:09

"This module has been discontinued. Use chaijs/pathval."

– Patrick Fisher
Mar 18 '14 at 0:09

add a comment |

The solutions here are just for accessing the deeply nested keys. I needed one for accessing, adding, modifying and deleting the keys. This is what I came up with:

var deepAccessObject = function(object, path_to_key, type_of_function, value){

    switch(type_of_function){

        //Add key/modify key

        case 0: 

            if(path_to_key.length === 1){

                if(value)

                    object[path_to_key[0]] = value;

                return object[path_to_key[0]];

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    object[path_to_key[0]] = {};

            }

            break;

        //delete key

        case 1:

            if(path_to_key.length === 1){

                delete object[path_to_key[0]];

                return true;

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    return false;

            }

            break;

        default:

            console.log("Wrong type of function");

    }

};

path_to_key: path in an array. You can replace it by your string_path.split(".").

type_of_function: 0 for accessing(dont pass any value to value), 0 for add and modify. 1 for delete.

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

add a comment |

The solutions here are just for accessing the deeply nested keys. I needed one for accessing, adding, modifying and deleting the keys. This is what I came up with:

var deepAccessObject = function(object, path_to_key, type_of_function, value){

    switch(type_of_function){

        //Add key/modify key

        case 0: 

            if(path_to_key.length === 1){

                if(value)

                    object[path_to_key[0]] = value;

                return object[path_to_key[0]];

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    object[path_to_key[0]] = {};

            }

            break;

        //delete key

        case 1:

            if(path_to_key.length === 1){

                delete object[path_to_key[0]];

                return true;

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    return false;

            }

            break;

        default:

            console.log("Wrong type of function");

    }

};

path_to_key: path in an array. You can replace it by your string_path.split(".").

type_of_function: 0 for accessing(dont pass any value to value), 0 for add and modify. 1 for delete.

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

add a comment |

The solutions here are just for accessing the deeply nested keys. I needed one for accessing, adding, modifying and deleting the keys. This is what I came up with:

var deepAccessObject = function(object, path_to_key, type_of_function, value){

    switch(type_of_function){

        //Add key/modify key

        case 0: 

            if(path_to_key.length === 1){

                if(value)

                    object[path_to_key[0]] = value;

                return object[path_to_key[0]];

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    object[path_to_key[0]] = {};

            }

            break;

        //delete key

        case 1:

            if(path_to_key.length === 1){

                delete object[path_to_key[0]];

                return true;

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    return false;

            }

            break;

        default:

            console.log("Wrong type of function");

    }

};

path_to_key: path in an array. You can replace it by your string_path.split(".").

type_of_function: 0 for accessing(dont pass any value to value), 0 for add and modify. 1 for delete.

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

The solutions here are just for accessing the deeply nested keys. I needed one for accessing, adding, modifying and deleting the keys. This is what I came up with:

var deepAccessObject = function(object, path_to_key, type_of_function, value){

    switch(type_of_function){

        //Add key/modify key

        case 0: 

            if(path_to_key.length === 1){

                if(value)

                    object[path_to_key[0]] = value;

                return object[path_to_key[0]];

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    object[path_to_key[0]] = {};

            }

            break;

        //delete key

        case 1:

            if(path_to_key.length === 1){

                delete object[path_to_key[0]];

                return true;

            }else{

                if(object[path_to_key[0]])

                    return deepAccessObject(object[path_to_key[0]], path_to_key.slice(1), type_of_function, value);

                else

                    return false;

            }

            break;

        default:

            console.log("Wrong type of function");

    }

};

path_to_key: path in an array. You can replace it by your string_path.split(".").

type_of_function: 0 for accessing(dont pass any value to value), 0 for add and modify. 1 for delete.

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

answered Jun 23 '16 at 9:45

ayushgp

2,16832146

add a comment |

Instead of a string an array can be used adressing nested objects and arrays e.g.: ["my_field", "another_field", 0, "last_field", 10]

Here is an example that would change a field based on this array representation. I am using something like that in react.js for controlled input fields that change the state of nested structures.

let state = {

        test: "test_value",

        nested: {

            level1: "level1 value"

        },

        arr: [1, 2, 3],

        nested_arr: {

            arr: ["buh", "bah", "foo"]

        }

    }



function handleChange(value, fields) {

    let update_field = state;

    for(var i = 0; i < fields.length - 1; i++){

        update_field = update_field[fields[i]];

    }

    update_field[fields[fields.length-1]] = value;

}



handleChange("update", ["test"]);

handleChange("update_nested", ["nested","level1"]);

handleChange(100, ["arr",0]);

handleChange('changed_foo', ["nested_arr", "arr", 3]);

console.log(state);

answered Oct 25 '17 at 8:12

Jodo

1,42611431

add a comment |

Instead of a string an array can be used adressing nested objects and arrays e.g.: ["my_field", "another_field", 0, "last_field", 10]

Here is an example that would change a field based on this array representation. I am using something like that in react.js for controlled input fields that change the state of nested structures.

let state = {

        test: "test_value",

        nested: {

            level1: "level1 value"

        },

        arr: [1, 2, 3],

        nested_arr: {

            arr: ["buh", "bah", "foo"]

        }

    }



function handleChange(value, fields) {

    let update_field = state;

    for(var i = 0; i < fields.length - 1; i++){

        update_field = update_field[fields[i]];

    }

    update_field[fields[fields.length-1]] = value;

}



handleChange("update", ["test"]);

handleChange("update_nested", ["nested","level1"]);

handleChange(100, ["arr",0]);

handleChange('changed_foo', ["nested_arr", "arr", 3]);

console.log(state);

answered Oct 25 '17 at 8:12

Jodo

1,42611431

add a comment |

Instead of a string an array can be used adressing nested objects and arrays e.g.: ["my_field", "another_field", 0, "last_field", 10]

Here is an example that would change a field based on this array representation. I am using something like that in react.js for controlled input fields that change the state of nested structures.

let state = {

        test: "test_value",

        nested: {

            level1: "level1 value"

        },

        arr: [1, 2, 3],

        nested_arr: {

            arr: ["buh", "bah", "foo"]

        }

    }



function handleChange(value, fields) {

    let update_field = state;

    for(var i = 0; i < fields.length - 1; i++){

        update_field = update_field[fields[i]];

    }

    update_field[fields[fields.length-1]] = value;

}



handleChange("update", ["test"]);

handleChange("update_nested", ["nested","level1"]);

handleChange(100, ["arr",0]);

handleChange('changed_foo', ["nested_arr", "arr", 3]);

console.log(state);

answered Oct 25 '17 at 8:12

Jodo

1,42611431

Instead of a string an array can be used adressing nested objects and arrays e.g.: ["my_field", "another_field", 0, "last_field", 10]

Here is an example that would change a field based on this array representation. I am using something like that in react.js for controlled input fields that change the state of nested structures.

let state = {

        test: "test_value",

        nested: {

            level1: "level1 value"

        },

        arr: [1, 2, 3],

        nested_arr: {

            arr: ["buh", "bah", "foo"]

        }

    }



function handleChange(value, fields) {

    let update_field = state;

    for(var i = 0; i < fields.length - 1; i++){

        update_field = update_field[fields[i]];

    }

    update_field[fields[fields.length-1]] = value;

}



handleChange("update", ["test"]);

handleChange("update_nested", ["nested","level1"]);

handleChange(100, ["arr",0]);

handleChange('changed_foo', ["nested_arr", "arr", 3]);

console.log(state);

answered Oct 25 '17 at 8:12

Jodo

1,42611431

answered Oct 25 '17 at 8:12

Jodo

1,42611431

answered Oct 25 '17 at 8:12

Jodo

1,42611431

answered Oct 25 '17 at 8:12

Jodo

1,42611431

add a comment |

Based on a previous answer, I have created a function that can also handle brackets. But no dots inside them due to the split.

function get(obj, str) {

  return str.split(/.|[/g).map(function(crumb) {

    return crumb.replace(/]$/, '').trim().replace(/^(["'])((?:(?!1)[^\]|\.)*?)1$/, (match, quote, str) => str.replace(/\(\)?/g, "$1"));

  }).reduce(function(obj, prop) {

    return obj ? obj[prop] : undefined;

  }, obj);

}

answered Nov 1 '17 at 12:44

Vincent

1,3571018

add a comment |

Based on a previous answer, I have created a function that can also handle brackets. But no dots inside them due to the split.

function get(obj, str) {

  return str.split(/.|[/g).map(function(crumb) {

    return crumb.replace(/]$/, '').trim().replace(/^(["'])((?:(?!1)[^\]|\.)*?)1$/, (match, quote, str) => str.replace(/\(\)?/g, "$1"));

  }).reduce(function(obj, prop) {

    return obj ? obj[prop] : undefined;

  }, obj);

}

answered Nov 1 '17 at 12:44

Vincent

1,3571018

add a comment |

Based on a previous answer, I have created a function that can also handle brackets. But no dots inside them due to the split.

function get(obj, str) {

  return str.split(/.|[/g).map(function(crumb) {

    return crumb.replace(/]$/, '').trim().replace(/^(["'])((?:(?!1)[^\]|\.)*?)1$/, (match, quote, str) => str.replace(/\(\)?/g, "$1"));

  }).reduce(function(obj, prop) {

    return obj ? obj[prop] : undefined;

  }, obj);

}

answered Nov 1 '17 at 12:44

Vincent

1,3571018

Based on a previous answer, I have created a function that can also handle brackets. But no dots inside them due to the split.

function get(obj, str) {

  return str.split(/.|[/g).map(function(crumb) {

    return crumb.replace(/]$/, '').trim().replace(/^(["'])((?:(?!1)[^\]|\.)*?)1$/, (match, quote, str) => str.replace(/\(\)?/g, "$1"));

  }).reduce(function(obj, prop) {

    return obj ? obj[prop] : undefined;

  }, obj);

}

answered Nov 1 '17 at 12:44

Vincent

1,3571018

answered Nov 1 '17 at 12:44

Vincent

1,3571018

answered Nov 1 '17 at 12:44

Vincent

1,3571018

answered Nov 1 '17 at 12:44

Vincent

1,3571018

add a comment |

// (IE9+) Two steps



var pathString = "[0]['property'].others[3].next['final']";

var obj = [{

  property: {

    others: [1, 2, 3, {

      next: {

        final: "SUCCESS"

      }

    }]

  }

}];



// Turn string to path array

var pathArray = pathString

    .replace(/[["']?([w]+)["']?]/g,".$1")

    .split(".")

    .splice(1);



// Add object prototype method

Object.prototype.path = function (path) {

  try {

    return [this].concat(path).reduce(function (f, l) {

      return f[l];

    });

  } catch (e) {

    console.error(e);

  }

};



// usage

console.log(obj.path(pathArray));

console.log(obj.path([0,"doesNotExist"]));

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

add a comment |

// (IE9+) Two steps



var pathString = "[0]['property'].others[3].next['final']";

var obj = [{

  property: {

    others: [1, 2, 3, {

      next: {

        final: "SUCCESS"

      }

    }]

  }

}];



// Turn string to path array

var pathArray = pathString

    .replace(/[["']?([w]+)["']?]/g,".$1")

    .split(".")

    .splice(1);



// Add object prototype method

Object.prototype.path = function (path) {

  try {

    return [this].concat(path).reduce(function (f, l) {

      return f[l];

    });

  } catch (e) {

    console.error(e);

  }

};



// usage

console.log(obj.path(pathArray));

console.log(obj.path([0,"doesNotExist"]));

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

add a comment |

// (IE9+) Two steps



var pathString = "[0]['property'].others[3].next['final']";

var obj = [{

  property: {

    others: [1, 2, 3, {

      next: {

        final: "SUCCESS"

      }

    }]

  }

}];



// Turn string to path array

var pathArray = pathString

    .replace(/[["']?([w]+)["']?]/g,".$1")

    .split(".")

    .splice(1);



// Add object prototype method

Object.prototype.path = function (path) {

  try {

    return [this].concat(path).reduce(function (f, l) {

      return f[l];

    });

  } catch (e) {

    console.error(e);

  }

};



// usage

console.log(obj.path(pathArray));

console.log(obj.path([0,"doesNotExist"]));

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

// (IE9+) Two steps



var pathString = "[0]['property'].others[3].next['final']";

var obj = [{

  property: {

    others: [1, 2, 3, {

      next: {

        final: "SUCCESS"

      }

    }]

  }

}];



// Turn string to path array

var pathArray = pathString

    .replace(/[["']?([w]+)["']?]/g,".$1")

    .split(".")

    .splice(1);



// Add object prototype method

Object.prototype.path = function (path) {

  try {

    return [this].concat(path).reduce(function (f, l) {

      return f[l];

    });

  } catch (e) {

    console.error(e);

  }

};



// usage

console.log(obj.path(pathArray));

console.log(obj.path([0,"doesNotExist"]));

// (IE9+) Two steps



var pathString = "[0]['property'].others[3].next['final']";

var obj = [{

  property: {

    others: [1, 2, 3, {

      next: {

        final: "SUCCESS"

      }

    }]

  }

}];



// Turn string to path array

var pathArray = pathString

    .replace(/[["']?([w]+)["']?]/g,".$1")

    .split(".")

    .splice(1);



// Add object prototype method

Object.prototype.path = function (path) {

  try {

    return [this].concat(path).reduce(function (f, l) {

      return f[l];

    });

  } catch (e) {

    console.error(e);

  }

};



// usage

console.log(obj.path(pathArray));

console.log(obj.path([0,"doesNotExist"]));

// (IE9+) Two steps



var pathString = "[0]['property'].others[3].next['final']";

var obj = [{

  property: {

    others: [1, 2, 3, {

      next: {

        final: "SUCCESS"

      }

    }]

  }

}];



// Turn string to path array

var pathArray = pathString

    .replace(/[["']?([w]+)["']?]/g,".$1")

    .split(".")

    .splice(1);



// Add object prototype method

Object.prototype.path = function (path) {

  try {

    return [this].concat(path).reduce(function (f, l) {

      return f[l];

    });

  } catch (e) {

    console.error(e);

  }

};



// usage

console.log(obj.path(pathArray));

console.log(obj.path([0,"doesNotExist"]));

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

answered Feb 23 '18 at 12:37

Oboo Chin

1,211818

add a comment |

Working with `Underscore`'s `property` or `propertyOf`:

var test = {

  foo: {

    bar: {

      baz: 'hello'

    }

  }

}

var string = 'foo.bar.baz';





// document.write(_.propertyOf(test)(string.split('.')))



document.write(_.property(string.split('.'))(test));

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>

Good Luck...

answered Jun 22 '18 at 11:49

Akash

6,32013840

add a comment |

Working with `Underscore`'s `property` or `propertyOf`:

var test = {

  foo: {

    bar: {

      baz: 'hello'

    }

  }

}

var string = 'foo.bar.baz';





// document.write(_.propertyOf(test)(string.split('.')))



document.write(_.property(string.split('.'))(test));

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>

Good Luck...

answered Jun 22 '18 at 11:49

Akash

6,32013840

add a comment |

Working with `Underscore`'s `property` or `propertyOf`:

var test = {

  foo: {

    bar: {

      baz: 'hello'

    }

  }

}

var string = 'foo.bar.baz';





// document.write(_.propertyOf(test)(string.split('.')))



document.write(_.property(string.split('.'))(test));

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>

Good Luck...

answered Jun 22 '18 at 11:49

Akash

6,32013840

Working with `Underscore`'s `property` or `propertyOf`:

var test = {

  foo: {

    bar: {

      baz: 'hello'

    }

  }

}

var string = 'foo.bar.baz';





// document.write(_.propertyOf(test)(string.split('.')))



document.write(_.property(string.split('.'))(test));

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>

Good Luck...

var test = {

  foo: {

    bar: {

      baz: 'hello'

    }

  }

}

var string = 'foo.bar.baz';





// document.write(_.propertyOf(test)(string.split('.')))



document.write(_.property(string.split('.'))(test));

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>

var test = {

  foo: {

    bar: {

      baz: 'hello'

    }

  }

}

var string = 'foo.bar.baz';





// document.write(_.propertyOf(test)(string.split('.')))



document.write(_.property(string.split('.'))(test));

<script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.9.1/underscore-min.js"></script>

answered Jun 22 '18 at 11:49

Akash

6,32013840

answered Jun 22 '18 at 11:49

Akash

6,32013840

answered Jun 22 '18 at 11:49

Akash

6,32013840

answered Jun 22 '18 at 11:49

Akash

6,32013840

add a comment |

Inspired by @webjay's answer:
https://stackoverflow.com/a/46008856/4110122

I made this function which can you use it to Get/ Set/ Unset any value in object

function Object_Manager(obj, Path, value, Action) 

{

    try

    {

        if(Array.isArray(Path) == false)

        {

            Path = [Path];

        }



        let level = 0;

        var Return_Value;

        Path.reduce((a, b)=>{

            level++;

            if (level === Path.length)

            {

                if(Action === 'Set')

                {

                    a[b] = value;

                    return value;

                }

                else if(Action === 'Get')

                {

                    Return_Value = a[b];

                }

                else if(Action === 'Unset')

                {

                    delete a[b];

                }

            } 

            else 

            {

                return a[b];

            }

        }, obj);

        return Return_Value;

    }



    catch(err)

    {

        console.error(err);

        return obj;

    }

}

To use it:

 // Set

 Object_Manager(Obj,[Level1,Level2,Level3],New_Value, 'Set');



 // Get

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Get');



 // Unset

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Unset');

edited Nov 29 '18 at 8:15

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

add a comment |

Inspired by @webjay's answer:
https://stackoverflow.com/a/46008856/4110122

I made this function which can you use it to Get/ Set/ Unset any value in object

function Object_Manager(obj, Path, value, Action) 

{

    try

    {

        if(Array.isArray(Path) == false)

        {

            Path = [Path];

        }



        let level = 0;

        var Return_Value;

        Path.reduce((a, b)=>{

            level++;

            if (level === Path.length)

            {

                if(Action === 'Set')

                {

                    a[b] = value;

                    return value;

                }

                else if(Action === 'Get')

                {

                    Return_Value = a[b];

                }

                else if(Action === 'Unset')

                {

                    delete a[b];

                }

            } 

            else 

            {

                return a[b];

            }

        }, obj);

        return Return_Value;

    }



    catch(err)

    {

        console.error(err);

        return obj;

    }

}

To use it:

 // Set

 Object_Manager(Obj,[Level1,Level2,Level3],New_Value, 'Set');



 // Get

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Get');



 // Unset

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Unset');

edited Nov 29 '18 at 8:15

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

add a comment |

Inspired by @webjay's answer:
https://stackoverflow.com/a/46008856/4110122

I made this function which can you use it to Get/ Set/ Unset any value in object

function Object_Manager(obj, Path, value, Action) 

{

    try

    {

        if(Array.isArray(Path) == false)

        {

            Path = [Path];

        }



        let level = 0;

        var Return_Value;

        Path.reduce((a, b)=>{

            level++;

            if (level === Path.length)

            {

                if(Action === 'Set')

                {

                    a[b] = value;

                    return value;

                }

                else if(Action === 'Get')

                {

                    Return_Value = a[b];

                }

                else if(Action === 'Unset')

                {

                    delete a[b];

                }

            } 

            else 

            {

                return a[b];

            }

        }, obj);

        return Return_Value;

    }



    catch(err)

    {

        console.error(err);

        return obj;

    }

}

To use it:

 // Set

 Object_Manager(Obj,[Level1,Level2,Level3],New_Value, 'Set');



 // Get

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Get');



 // Unset

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Unset');

edited Nov 29 '18 at 8:15

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

Inspired by @webjay's answer:
https://stackoverflow.com/a/46008856/4110122

I made this function which can you use it to Get/ Set/ Unset any value in object

function Object_Manager(obj, Path, value, Action) 

{

    try

    {

        if(Array.isArray(Path) == false)

        {

            Path = [Path];

        }



        let level = 0;

        var Return_Value;

        Path.reduce((a, b)=>{

            level++;

            if (level === Path.length)

            {

                if(Action === 'Set')

                {

                    a[b] = value;

                    return value;

                }

                else if(Action === 'Get')

                {

                    Return_Value = a[b];

                }

                else if(Action === 'Unset')

                {

                    delete a[b];

                }

            } 

            else 

            {

                return a[b];

            }

        }, obj);

        return Return_Value;

    }



    catch(err)

    {

        console.error(err);

        return obj;

    }

}

To use it:

 // Set

 Object_Manager(Obj,[Level1,Level2,Level3],New_Value, 'Set');



 // Get

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Get');



 // Unset

 Object_Manager(Obj,[Level1,Level2,Level3],'', 'Unset');

edited Nov 29 '18 at 8:15

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

edited Nov 29 '18 at 8:15

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

answered Nov 28 '18 at 23:35

Mohamad Hamouday

34748

add a comment |

-1

What about this solution:

setJsonValue: function (json, field, val) {

  if (field !== undefined){

    try {

      eval("json." + field + " = val");

    }

    catch(e){

      ;

    }

  }  

}

And this one, for getting:

getJsonValue: function (json, field){

  var value = undefined;

  if (field !== undefined) {

    try {

      eval("value = json." + field);

    } 

    catch(e){

      ;

    }

  }

  return value;

};

Probably some will consider them unsafe, but they must be much faster then, parsing the string.

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

add a comment |

-1

What about this solution:

setJsonValue: function (json, field, val) {

  if (field !== undefined){

    try {

      eval("json." + field + " = val");

    }

    catch(e){

      ;

    }

  }  

}

And this one, for getting:

getJsonValue: function (json, field){

  var value = undefined;

  if (field !== undefined) {

    try {

      eval("value = json." + field);

    } 

    catch(e){

      ;

    }

  }

  return value;

};

Probably some will consider them unsafe, but they must be much faster then, parsing the string.

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

add a comment |

-1

What about this solution:

setJsonValue: function (json, field, val) {

  if (field !== undefined){

    try {

      eval("json." + field + " = val");

    }

    catch(e){

      ;

    }

  }  

}

And this one, for getting:

getJsonValue: function (json, field){

  var value = undefined;

  if (field !== undefined) {

    try {

      eval("value = json." + field);

    } 

    catch(e){

      ;

    }

  }

  return value;

};

Probably some will consider them unsafe, but they must be much faster then, parsing the string.

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

What about this solution:

setJsonValue: function (json, field, val) {

  if (field !== undefined){

    try {

      eval("json." + field + " = val");

    }

    catch(e){

      ;

    }

  }  

}

And this one, for getting:

getJsonValue: function (json, field){

  var value = undefined;

  if (field !== undefined) {

    try {

      eval("value = json." + field);

    } 

    catch(e){

      ;

    }

  }

  return value;

};

Probably some will consider them unsafe, but they must be much faster then, parsing the string.

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

answered Dec 4 '13 at 19:54

Jonan Georgiev

461410

add a comment |

-1

Building off of Alnitak's answer:

if(!Object.prototype.byString){

  //NEW byString which can update values

Object.prototype.byString = function(s, v, o) {

  var _o = o || this;

      s = s.replace(/[(w+)]/g, '.$1'); // CONVERT INDEXES TO PROPERTIES

      s = s.replace(/^./, ''); // STRIP A LEADING DOT

      var a = s.split('.'); //ARRAY OF STRINGS SPLIT BY '.'

      for (var i = 0; i < a.length; ++i) {//LOOP OVER ARRAY OF STRINGS

          var k = a[i];

          if (k in _o) {//LOOP THROUGH OBJECT KEYS

              if(_o.hasOwnProperty(k)){//USE ONLY KEYS WE CREATED

                if(v !== undefined){//IF WE HAVE A NEW VALUE PARAM

                  if(i === a.length -1){//IF IT'S THE LAST IN THE ARRAY

                    _o[k] = v;

                  }

                }

                _o = _o[k];//NO NEW VALUE SO JUST RETURN THE CURRENT VALUE

              }

          } else {

              return;

          }

      }

      return _o;

  };

}

This allows you to set a value as well!

I've created an npm package and github with this as well

edited Aug 15 '17 at 21:40

answered Aug 2 '17 at 19:16

Tamb

16919

add a comment |

-1

Building off of Alnitak's answer:

if(!Object.prototype.byString){

  //NEW byString which can update values

Object.prototype.byString = function(s, v, o) {

  var _o = o || this;

      s = s.replace(/[(w+)]/g, '.$1'); // CONVERT INDEXES TO PROPERTIES

      s = s.replace(/^./, ''); // STRIP A LEADING DOT

      var a = s.split('.'); //ARRAY OF STRINGS SPLIT BY '.'

      for (var i = 0; i < a.length; ++i) {//LOOP OVER ARRAY OF STRINGS

          var k = a[i];

          if (k in _o) {//LOOP THROUGH OBJECT KEYS

              if(_o.hasOwnProperty(k)){//USE ONLY KEYS WE CREATED

                if(v !== undefined){//IF WE HAVE A NEW VALUE PARAM

                  if(i === a.length -1){//IF IT'S THE LAST IN THE ARRAY

                    _o[k] = v;

                  }

                }

                _o = _o[k];//NO NEW VALUE SO JUST RETURN THE CURRENT VALUE

              }

          } else {

              return;

          }

      }

      return _o;

  };

}

This allows you to set a value as well!

I've created an npm package and github with this as well

edited Aug 15 '17 at 21:40

answered Aug 2 '17 at 19:16

Tamb

16919

add a comment |

-1

Building off of Alnitak's answer:

if(!Object.prototype.byString){

  //NEW byString which can update values

Object.prototype.byString = function(s, v, o) {

  var _o = o || this;

      s = s.replace(/[(w+)]/g, '.$1'); // CONVERT INDEXES TO PROPERTIES

      s = s.replace(/^./, ''); // STRIP A LEADING DOT

      var a = s.split('.'); //ARRAY OF STRINGS SPLIT BY '.'

      for (var i = 0; i < a.length; ++i) {//LOOP OVER ARRAY OF STRINGS

          var k = a[i];

          if (k in _o) {//LOOP THROUGH OBJECT KEYS

              if(_o.hasOwnProperty(k)){//USE ONLY KEYS WE CREATED

                if(v !== undefined){//IF WE HAVE A NEW VALUE PARAM

                  if(i === a.length -1){//IF IT'S THE LAST IN THE ARRAY

                    _o[k] = v;

                  }

                }

                _o = _o[k];//NO NEW VALUE SO JUST RETURN THE CURRENT VALUE

              }

          } else {

              return;

          }

      }

      return _o;

  };

}

This allows you to set a value as well!

I've created an npm package and github with this as well

edited Aug 15 '17 at 21:40

answered Aug 2 '17 at 19:16

Tamb

16919

Building off of Alnitak's answer:

if(!Object.prototype.byString){

  //NEW byString which can update values

Object.prototype.byString = function(s, v, o) {

  var _o = o || this;

      s = s.replace(/[(w+)]/g, '.$1'); // CONVERT INDEXES TO PROPERTIES

      s = s.replace(/^./, ''); // STRIP A LEADING DOT

      var a = s.split('.'); //ARRAY OF STRINGS SPLIT BY '.'

      for (var i = 0; i < a.length; ++i) {//LOOP OVER ARRAY OF STRINGS

          var k = a[i];

          if (k in _o) {//LOOP THROUGH OBJECT KEYS

              if(_o.hasOwnProperty(k)){//USE ONLY KEYS WE CREATED

                if(v !== undefined){//IF WE HAVE A NEW VALUE PARAM

                  if(i === a.length -1){//IF IT'S THE LAST IN THE ARRAY

                    _o[k] = v;

                  }

                }

                _o = _o[k];//NO NEW VALUE SO JUST RETURN THE CURRENT VALUE

              }

          } else {

              return;

          }

      }

      return _o;

  };

}

This allows you to set a value as well!

I've created an npm package and github with this as well

edited Aug 15 '17 at 21:40

answered Aug 2 '17 at 19:16

Tamb

16919

edited Aug 15 '17 at 21:40

answered Aug 2 '17 at 19:16

Tamb

16919

answered Aug 2 '17 at 19:16

Tamb

16919

answered Aug 2 '17 at 19:16

Tamb

16919

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protected by Samuel Liew♦ Oct 5 '15 at 9:21

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