can't use \verb to print "%"

[syvshc]

Here is my mwe:

\documentclass{article}
\usepackage{tabularray}
\usepackage{fancyvrb}
\begin{document}
    \begin{tblr}{verb}
        \verb|a|\\
        \verb|%|\\  % This line doesn't work and will cause an error
        \verb|\%|   % This line works
    \end{tblr}\par
    \begin{tblr}{columns = {appto={|}, preto={\Verb|}}}
        a \\
        % \\        % This line is considered commented
        \%          % This line outputs %, not \%
    \end{tblr}\par
    \verb|%|
\end{document}

The error which \verb|%| gives is

! LaTeX Error: \verb ended by end of line.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...

l.6     \end
            {tblr}
? x

[lvjr]

The % and characters after it are removed by TeX before tabularray or tabularx sees them. You need to change the catcode of % character to make TeX treat it as a normal character.

\documentclass{article}

\usepackage{tabularray}
\usepackage{tabularx}
\usepackage{fancyvrb}

\begin{document}

For \texttt{tabularray}:

\begingroup
\catcode`\%=12
\begin{tblr}{verb}
    \verb|a| \\
    \verb|%| \\
    \verb|\%|
\end{tblr}
\quad
\begin{tblr}{verb,columns={preto={\Verb|},appto={|}}}
    a \\
    % \\
    \% 
\end{tblr}
\endgroup

For \texttt{tabularx}:

\begingroup
\catcode`\%=12
\begin{tabularx}{\linewidth}{X}
    \verb|a|\\
    \verb|%|\\
    \verb|\%|
\end{tabularx}
\endgroup

\end{document}

See also https://tex.stackexchange.com/questions/499125/verb-with-in-tabularx

[lvjr]

Since version 2023A, verb option was obsolete. Please use \fakeverb command from codehigh package instead.