Put \ref{} within \aaalphanum

Question

I'm trying to ref a label using \ref and output an alphabetical letter (e.g. 'A') rather than the number (e.g. 1).

I have read somewhere to use \AAAlphanum{\ref{my_label}} but this command fails

Missing number, treated as zero.

Any help is greatly appreciated.

Answer 1

There are a number of ways you can achieve this:

\documentclass{article}
\usepackage{zref,refcount,alphalph,hyperref}

\makeatletter
\zref@newprop{AlphAlphcntr}[??]{\AlphAlph{\value{section}}}
\newcommand{\mylabel}[1]{\zref@labelbyprops{#1}{AlphAlphcntr}}
\newcommand{\myref}[1]{\zref@refused{#1}\zref@extract{#1}{AlphAlphcntr}}
\makeatother

\setlength{\parindent}{0pt}% Just for this example

\begin{document}

\section{A section}\label{sec:mysection}\mylabel{sec:mysection}
Section~\ref{sec:mysection}. \par
Section~\AlphAlph{\getrefnumber{sec:mysection}}. \par
Section~\myref{sec:mysection}.

\end{document}

The first reference uses \ref, which defaults to whatever the \the<counter> is set to (in this case, \arabic{section}). The second reference uses the expandable \getrefnumber provided by refcount. The last reference uses a custom property list (with the aid of zref) to only store and/or retrieve the \AlphAlph-version of the section counter.

All of the above can be extended to use hyperref, of course.