Boxes with equal height

Question

I am looking for a simple way to make the following boxes the same height.

\documentclass{article}

\setlength{\parindent}{0pt}

\begin{document}

\fbox{\hbox to 0.3\linewidth{\vbox{test}}}%
\hfill
\fbox{\hbox to 0.3\linewidth{\vbox{test\par{}test\par{}test}}}%
\hfill
\fbox{\hbox to 0.3\linewidth{\vbox{test\par{}test}}}

\end{document}

I have experimented with calculating the maximum of the heights of the boxes and setting them with the settobox package but I am wondering whether there might be a simpler way. Please note that I do not know the height of any of the boxes beforehand and that I am looking for a method that also scales when there are more than three boxes.

Answer 1

\documentclass{article}
\begin{document}    
\fbox{\parbox[b][2.5\baselineskip]{0.3\linewidth}{test}}
\fbox{\parbox[b][2.5\baselineskip]{0.3\linewidth}{test\par{}test\par{}test}}
\fbox{\parbox[b][2.5\baselineskip]{0.3\linewidth}{test\par{}test}}
\end{document}

\parbox[<vpos>][<height>]{<width>}{<contents>}

or for a variable height which needs a test:

\documentclass{article}
\newsavebox\VBox
\begin{document}
\savebox\VBox{\parbox{0.3\linewidth}{test\par test\par test\par}}

\noindent
\fbox{\parbox[b][\dimexpr\ht\VBox+\dp\VBox]{0.3\linewidth}{test}}
\fbox{\parbox[b][\dimexpr\ht\VBox+\dp\VBox]{0.3\linewidth}{test\par test\par test}}
\fbox{\parbox[b][\dimexpr\ht\VBox+\dp\VBox]{0.3\linewidth}{test\par test}}

\end{document}

Answer 2

This could be a another job for tcolorbox, if you like. Its option equal height group allows to set a group of boxes to the same height. The example code below produces a new kind of \fbox called \mybox here. It has an optional parameter to specify another equal height group, if you have several ones.

My example is specific, of course, but the option can be used for any number of boxes and does not need xparse which I used for the example. The current version 3.12 (2014/07/29) describes the option on page 42 of the documentation.

Note: The example has to be compiled twice.

\documentclass{article}

\usepackage[xparse]{tcolorbox}
\usepackage{lipsum}
\setlength{\parindent}{0pt}

\begin{document}

\NewTotalTColorBox{\mybox}{ O{once} +m }{size=fbox,sharp corners,
  colframe=blue!50!black,colback=yellow!10!white,
  width=0.3\linewidth,nobeforeafter,equal height group=#1}{#2}

\mybox{test}%
\hfill
\mybox{test\par{}test\par{}test}%
\hfill
\mybox{test\par{}test}\par

\bigskip

{
\footnotesize
\mybox[other]{\lipsum[1]}%
\hfill
\mybox[other]{\lipsum[2]}%
\hfill
\mybox[other]{\lipsum[3]}\par
}

\end{document}