Can you iterate in LaTeX?

Question

I'm new to LaTeX and I must say that I am really struggling with it. I discovered the \newcommand command that is kind of like a function/method in regular programming languages. You can give it arguments and everything.

I was wondering though, can I somehow iterate in LaTeX? Basically, what I would like to do is create a table with N+1 columns where the first row just contains a blank cell and then the numbers 1, 2, ..., N in the other columns. I only want to give N as an argument to this 'function' (newcommand).

Here is an example of something that might look like what I'm looking for (although obviously this won't work):

\newcommand{\mytable}[2]{  
\begin{tabular}{l|*{#1}{c|}} % table with first argument+1 columns  
  for(int i = 1; i <= #1; i++) "& i" % 'output' numbers in different columns  
  \\\hline  
  letters & #2 % second argument should contain actual content for row  
  \\\hline  
\end{tabular}  
}

Call it with:

\mytable{3}{a & b & c}

Output should be:

        | 1 | 2 | 3 |
--------+---+---+---+
letters | a | b | c |
--------+---+---+---+

Does anyone know if something like this is possible?

Thanks!

Answer 1

Auntie Google says yes.

Answer 2

Just make the following into a new command and be sure to use package ifthen.

\begin{tabular}{l|*{10}{c|}}
\newcounter{count}
\whiledo{\value{count}<10}{
\ifthenelse{\value{count}=0}{}{\the\value{count}}
\ifthenelse{\value{count}<9}{&}{\\}
\stepcounter{count}
}
letters&a&b&c&d&e&f&g&h&i\\
\end{tabular}

Answer 3

You can use the \loop or \repeat tokens. Or the multido package.

Answer 4

Sure it's possible. You can also recur. eplain has iteration macros in it, see, eg, here.

Answer 5

Another possibility (if you're lazy like me) is perltex