Columns width of array environment

Question

I'm using the array environment and have something like this:

\begin{array}{|c|c|}
   \hline 
   \textbf{x} & \textbf{y} \\ 
   \hline
   \hline
   t_1 & lon_1 \\ 
   \hline 
\end{array}

I would like to have the two columns to have the same width. How can I do that?

Answer 1

If you don't want to use the the p{<width>} column type where you have to fix the width to a specific amount you could typeset one row using the SetToWidest macro as defined below. This requires that you determine what the widest entry is and define that as the value of WidestEntry:

\documentclass{article}
\usepackage{calc}

\newcommand{\WidestEntry}{$lon_1$}%
\newcommand{\SetToWidest}[1]{\makebox[\widthof{\WidestEntry}]{#1}}%

\begin{document}
\begin{tabular}{|c|c|}
   \hline 
   \textbf{x} & \textbf{y} \\ 
   \hline
   \hline
   \SetToWidest{$t_1$} & $lon_1$ \\ 
   \hline 
\end{tabular}

or similarly using array:

\documentclass{article}
\usepackage{calc}

\newcommand{\WidestEntry}{$lon_1$}%
\newcommand{\SetToWidest}[1]{\makebox[\widthof{\WidestEntry}]{$#1$}}%

\begin{document}$
\begin{array}{|c|c|}
   \hline 
   \textbf{x} & \textbf{y} \\ 
   \hline
   \hline
   \SetToWidest{t_1} & lon_1 \\ 
   \hline 
\end{array}$
\end{document}

---

If you are ok with specifying the width of each column you can use the p{<width>} column type:

\documentclass{article}
\usepackage{array}

\begin{document}$
\begin{array}{|>{\centering\arraybackslash$} p{1.0cm} <{$} | >{\centering\arraybackslash$} p{1.0cm} <{$} |}
   \hline 
   \textbf{x} & \textbf{y} \\ 
   \hline
   \hline
   t_1 & lon_1 \\ 
   \hline 
\end{array}$
\end{document}