Extracting text from variable

Question

I am trying to work out a special document that through a seed generates a test for my students. I have gotten quite alot to work but I have the issue that when I try to add my answers into an array (which I use to store the answers to be printed on a seperate sheet for myself).

\newcommand\setans[2]{%
\csdef{answer#1}{#2}}
\newcommand\addans[1]{%
\stepcounter{a}%
\csdef{answer\thea}{#1}}
\newcommand\getans[1]{%
\csuse{answer#1}}

This is what I use for my array and I store things in the manner of

\addans{\answer}

the issue is of course due to my algorithms the \answer variable changes along the line so when it comes to the end of the document it will just display for all positions the last \answer's value, is there a way to extract the text of \answer that I then use on \addans, or another way to go about it?

Best regards

Answer 1

Behold my psychic power! Use \cslet to set \answer1 etc. to the current definition of \answer, not answer itself.

\documentclass{article}
\usepackage{etoolbox}
\newcounter{a}
\setcounter{a}{0}

\newcommand\setans[2]{%
  \csdef{answer#1}{#2}}

\newcommand\addans[1]{%
  \stepcounter{a}%
  \cslet{answer\thea}{#1}} %  <--- Not \csdef!

\newcommand\getans[1]{%
  \csuse{answer#1}}

\begin{document}

\def\answer{42}
\addans{\answer}
\def\answer{99}
\addans{\answer}

\getans{1}

\getans{2}
\end{document}

EDIT

If you want do more than just \addans{\answer} you can try the following definition for \addans.

\makeatletter
\newcommand\addans[1]{%
  \stepcounter{a}%
  \edef\@tmp{#1}
  \cslet{answer\thea}\@tmp} %  <--- Not \csdef!
\makeatother

This will work for the example you gave (i.e. \addans{C=\answer}), but if you try anything too elaborate it will probably break (in which case you might need to ask a new question in order to gain the attention of someone like egreg or David Carlisle).