Variable number of arguments in a command

Question

Code

\documentclass{article}
\newcommand*\test[2]{#1\textsuperscript{#2}}
\begin{document}
The player ended as no.~\test{1}{} and her friend came in \test{2}{nd}.
\end{document}

Output

Question

How can I change the \test command so that I'm abel to switch between one or two arguments?

(I would like to be abel to write \test{1} instead of \test{1}{}.)

Optional arguments for LaTeX2e commands are given in square brackets! — Joseph Wright, Jan 17 '16 at 10:53
@JosephWright Sorry. I mixed things up; I'll rephrase my question. — Svend Tveskæg, Jan 17 '16 at 10:54
For easy usage of optional arguments: \NewDocumentCommand ;-) — , Jan 17 '16 at 10:55
@SvendTveskæg You might want to be able to use \test{1} and \test{2}{nd}, but I'm recommending not to. — egreg, Jan 17 '16 at 11:03
@SvendTveskæg Joseph already told you: if an argument is optional, treat it as such. — egreg, Jan 17 '16 at 11:05
While it is possible to do this it is a really bad idea to do it in a latex2e context. LaTeX2e commands never take a variable number of {} arguments. A major aim of the system is to give a consistent interface to arguments. If an argument is optional it should be in square brackets. — David Carlisle, Jan 17 '16 at 11:12
Related: macros - Commands that may take a variable number of arguments - TeX - LaTeX Stack Exchange — user202729, Dec 30 '22 at 02:59

score 8 · Answer 1 · 2016-01-17T11:09:53.853

8

With xparse the feature can be done easily with the g optional argumen t specifier, but optional arguments should be done with [...], i.e. use o rather, in my point of view!

\documentclass{article}
\usepackage{xparse}


\NewDocumentCommand{\test}{mg}{#1\IfValueT{#2}{\textsuperscript{#2}}}
\begin{document}
The player ended as no.~\test{1} and her friend came as \test{2}{nd}.
\end{document}

edited Jan 17 '16 at 11:09

answered Jan 17 '16 at 10:58

I would like to be abel to write \test{1} and \test{2}{nd} (or \test{5} and \test{8}{th}, ect.). – Svend Tveskæg Jan 17 '16 at 11:00
1

@SvendTveskæg: That's easy: Use g instead of o as optional argument specifier! – Jan 17 '16 at 11:02
I actually like Werner approach better (even though I asked for the solution you have given). – Svend Tveskæg Jan 17 '16 at 17:37
@SvendTveskæg: You asked for this and I provided this -- now you unaccept. I am sure you know that is not kosher at all. – Jan 17 '16 at 19:14
I didn't knew that but we can't have that you are upset about it. – Svend Tveskæg Jan 17 '16 at 19:41

score 3 · Accepted Answer · answered Jan 17 '16 at 17:25

3

I'd suggest an alternative interface using * (say):

\documentclass{article}

\usepackage{fmtcount}

\makeatletter
\newcommand{\@test}[1]{#1}
\newcommand{\@@test}[1]{\ordinalnum{#1}}
\newcommand{\test}{\@ifstar\@test\@@test}
\makeatother

\begin{document}

\test{1} \test*{1}

\test{2} \test*{2}

\test{11} \test{12} \test{21}
\end{document}

The above command definition is also possible using xparse:

\usepackage{xparse}
\NewDocumentCommand{\test}{s m}
  {\IfBooleanTF{#1}{#2}{\ordinalnum{#2}}}

answered Jan 17 '16 at 17:25

Werner

603,163

Great! What if I want the starred version to give the ordinal number? – Svend Tveskæg Jan 17 '16 at 17:50
1

@SvendTveskæg: Then use \newcommand{\test}{\@ifstar\@@test\@test} or \NewDocumentCommand{\test}{s m}{\IfBooleanTF{#1}{\ordinalnum{#2}}{#2}}. – Werner Jan 17 '16 at 17:55
1

@SvendTveskæg: You can accept any answer that helped you the most. – Werner Jan 17 '16 at 19:57
Okay. I think that Christian is rather childish so I'll let him have the 15 points reward but I'll remember your advise for next time. – Svend Tveskæg Jan 18 '16 at 14:37
@SvendTveskæg: :) – Werner Jan 18 '16 at 14:49

score 0 · Answer 3 · answered Jan 17 '16 at 19:24

\documentclass[a4paper]{article}
\newcommand\test[2][]{#2\ifx\relax#1\relax\else\textsuperscript{#1}\fi}
\begin{document}
The player ended as no.~\test{1} and her friend came ind \test[nd]{2}.
\end{document}

Variable number of arguments in a command

3 Answers3

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