Cfrgtkky

I used whileboolexpr command from etoolbox package to generate a table. But there was an extra unwanted row. What is the problem with the following code?

documentclass[12pt]{article}



usepackage{etoolbox}



begin{document}



newcounter{row}

newcounter{rowcount}

newcommand{myand}{&}



newcommand{mylines}{%

  setcounter{rowcount}{0}%

  whileboolexpr{

      test{ifnumless{value{rowcount}}{value{row}}}

  }{%

      stepcounter{rowcount}%

      Number myand 1 myand 2 myand 3 \ hline

  }%

}



newcommand{mytable}[1]{

  setcounter{row}{#1}%

  begin{tabular}{|c|*{3}{c|}}

    hline

    mylines

  end{tabular}%

}



mytable{4}



end{document}

As egreg says, LaTeX starts the next cell before it realises that the table has finished. I realise that your real application is more complex, but a really efficient way to implement your MWE is using prg_replicate:nn from LaTeX3 to produce:

Here's the code:

documentclass{article}

usepackage{expl3}

ExplSyntaxOn

newcommandmytable[1]{%

  begin{tabular}{|c|*{3}{c|}}hline

    prg_replicate:nn {#1} {Number &1&2&3\hline}

  end{tabular}%

}

ExplSyntaxOff

begin{document}



  mytable{4}



end{document}

Edit

Given the comment below, here is a more general approach that might be closer to what is required. It produces

from the input

  mytable{

    {one  &1&2&3},

    {two  &4&6},

    {three&1},

    {four &1&2&2}

  }

where one, two, ... are some random macros.

The mytable macro accepts a comma separated list of table-rows. By default the table has four columns but this can be changes with an optional argument so that, for example, mytable[6]{...} gives a table with 6 columns. There is an obvious issue here with "dangling hlines. This is easy enough to fix but as the OP does not gives details as to what is actually required there is little doing this without more information. For the reasons explained in the booktabs manual I'd drop the vertical rules and use toprule and bottomrule for the top and bottom rules, this would fix this problem and produce:

Here's the code:

documentclass{article}

usepackage{expl3}

usepackage{booktabs}



ExplSyntaxOn

clist_new:N l_table_clist

newcommandmytable[2][4]{

  clist_set:Nn l_table_clist {#2}

  begin{tabular}{*{#1}{c}}toprule

    clist_use:Nn l_table_clist {\hline}

    \bottomrule

  end{tabular}%

}

ExplSyntaxOff



begin{document}



  newcommandone{One}

  newcommandtwo{Two}

  newcommandthree{Three}

  newcommandfour{Four}

  mytable{

    {one&1&2&3},

    {two& 4&6},

    {three& 1},

    {four&1&2&2}

  }



end{document}

My weekly (some say daily) xintFor exercise.

documentclass[12pt]{article}



usepackage{xinttools}



newcommand{mytable}[1]{

  begin{tabular}{|c|*{3}{c|}}

    hline

    xintFor* ##1 in {xintSeq{1}{#1}}:

    {%

      Number & 1 & 2 & 3 \ hline

    }%

  end{tabular}%

}



begin{document}



mytable{4}



end{document}

You can generate the row code outside of the tabular:

documentclass{article}



usepackage{etoolbox}



begin{document}



newcounter{row}

newcommand{myand}{&}



makeatletter

newcommand{mylines}[1]{%

  setcounter{row}{#1}%

  def@mylines{}%

  whileboolexpr{%

      test{ifnumless{0}{value{row}}}%

  }{%

      addtocounter{row}{-1}%

      xdef@mylines{@mylines hline

        Number myand 1 myand 2 myand 3 \

      }%

  }%

}



newcommand{mytable}[1]{%

  {lethlinerelax % Avoid expansion of hline in xdef

   let\relax % Avoid expansion of \ in xdef

   mylines{#1}}% This generates @mylines

  begin{tabular}{ | c | *{3}{c|} }

    @mylines hline % Print @mylines

  end{tabular}%

}

makeatother



mytable{4}



end{document}