Compare the height of arguments

Question

I'm trying to define a \newcommand with three arguments. I'd like to:

• compare the height of these arguments
• choose the largest height to create frames (with that height) around the arguments.

Question

How can I compare these three arguments to choose the tallest?

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First Update

Following the advise by David Calister, I defined a command which insert all the arguments in a box and return the height of the box, and also defined a new lenght (called MyLen).

The following code,

\documentclass{minimal}
\usepackage{calc}
\newcommand\zz[3]{\sbox0{\ensuremath{#1#2#3}}\the\ht0}
\newlength{\MyLen}

\begin{document}
\zz{1}{2}{\frac{3}{4}}
\zz{1}{2}{3}
\end{document}

results into

Well Done so far!

Then, I'd like to set MyLen to be such result, using

\documentclass{minimal}
\usepackage{calc}
\newcommand\zz[3]{\sbox0{\ensuremath{#1#2#3}}\the\ht0}
\newlength{\MyLen}

\begin{document}
\zz{1}{2}{\frac{3}{4}}

\zz{1}{2}{3}

\settoheight\MyLen{\zz{1}{2}{\frac{3}{4}}}
\the\MyLen
\end{document}

but the result is wrong (the last value should be equal to the first one)

What is happening? Where is my mistake?

Answer 1

\newcommand\zz[3]{%
\sbox0{#1#2#3}%
\showthe\ht0
}