I would like to extend my previous question and know how to type a comment, using delimiters, in any table cell to be suppressed in the compiled PDF without the need to use, for example, \iffalse...\fi.
For instance, here, the comment delimiters are << and >>.
\documentclass[border=1cm]{standalone}
\begin{document}
\begin{tabular}{cc}
\hline
1st entry <<1st comment>> & 2nd entry <<2nd comment>> \\
\hline
\end{tabular}
\end{document}

<<and>>as comment delimiters. It is easier to handle without the need to define commands, especially in large tables. – Diaa Apr 16 '17 at 19:16\comment{1st comment}which can trivially be defined as\newcommand\comment[1]{}? Or why not use standard TeX comment%– David Carlisle Apr 16 '17 at 20:00