LaTeX error: illegal parameter number in definition of \pgffor@b

Question

I am trying to use a loop. The following does not work:

\foreach \a in {no,has}{    
    \begin{table}[H]
    \footnotesize
    \captionsetup{width=.9\linewidth}
    \caption{text}
    \vspace{-22pt}
    \label{}
    \begin{center}
    {
    \def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
    \begin{tabular}{l*{6}{c}}
    \toprule \toprule \\
    ~~~~text \\
    \hline
    \input{../text1_\a_c.tex}
    \hline \\
    ~~~~text \\
    \hline
    \input{../text2_\a_c.tex}
    \hline
    \bottomrule
    \end{tabular}
    }
    \end{center}
    \caption*{\begin{footnotesize}  \end{footnotesize}}
    \end{table}
}

What I am trying to do is to access four similarly-named files with the loop — two the first time through (named ...no...) and two the second time through (named ...has...).

I get this error:

illegal parameter number in definition of \pgffor@b

Note that the following does work:

This works:

\foreach \a in {no,has}{
\a
}

What should I try to fix this?

Answer 1

Since the definition of \sym occurs in the argument to another command, it should be

\def\sym##1{\ifmmode^{##1}\else\(^{##1}\)\fi}

in this code.