Measure the length of the lowercase alphabet

Question

In the memoir manual speaks about

measuring the length of the lowercase alphabet

in order to decide the numbers of characters per line. Can this be done with LaTeX?

Answer 1

If with the length it means the width of all lowercase letters than you can use \settowidth{<length register>}{<content>}:

\documentclass{article}
\begin{document}
  \newlength{\alphabetlength}
  \settowidth{\alphabetlength}{abcdefghijklmnopqrstuvwxyz}
  \the\alphabetlength
\end{document}

(I took the liberty to use the same format as Yiannis answer to allow for better comparison. His answer is fine too, but I wanted to show the official LaTeX way.)

Answer 2

You can place the letters in a box and measure its length. Here is a minimal to do this.

\documentclass{article}
\begin{document}
  \newbox\alphabet
  \sbox\alphabet{abcdefghijklmnopqrstuvwxyz}
  \the\wd\alphabet
\end{document}

Answer 3

Just for the record, page 15 of memman.pdf brings the following to print the length of the lowercase alphabet:

\newlength{\mylen}                % a length
\newcommand{\alphabet}{abc...xyz} % the lowercase alphabet
\begingroup                       % keep font change local
% font specification e.g., \Large\sffamily
\settowidth{\mylen}{\alphabet}
The length of this alphabet is \the\mylen. % print in document
\typeout{The length of the Large sans alphabet
    is \the\mylen}                         % put in log file
\endgroup                         % end the grouping

Which is basically @Martin's way.