Time for action – merging cells

Regarding our example table, commands and declarations are both input, whereas, the remaining column contains output. We shall emphasize that in our header:

1. In our example, insert another header row. Use \multicolumn to merge cells. Alter the column formatting argument and the middle rule. Changes are highlighted:

   \begin{tabular}{@{}*3l@{}}
     \toprule[1.5pt]
     \multicolumn{2}{c}{\head{Input}} &
     \multicolumn{1}{c}{\head{Output}}\\
     \head{Command} & \head{Declaration} & \\
     \cmidrule(r){1-2}\cmidrule(l){3-3}
     \verb|\textrm| & \verb|\rmfamily| & \rmfamily Example text\\
     \verb|\textsf| & \verb|\sffamily| & \sffamily Example text\\
     \verb|\texttt| & \verb|\ttfamily| & \ttfamily Example text\\
     \bottomrule[1.5pt]
   \end{tabular}

2. Typeset and see the output:

   

What just happened?

We used the command \multicolumn twice; once to merge two cells and surprisingly another time just for one cell. Let's first look at its definition:

\multicolumn...