# Chapter 13 – Troubleshooting

Here are the Code examples of of this chapter. You can compile them online right on this web page by pressing the Typeset / Compile button. You can also edit them for testing, and compile again.

For a better view with the online compiler, I sometimes use \documentclass[border=10pt]{standalone} instead of \documentclass{article}. Instead of having a big letter/A4 page, the standalone class crops the paper to see just the visible text without an empty rest of a page.

#### Error testing

\documentclass{article}
\begin{document}
% wrong:
%\Latex\ says: Hello world!
% correct:
\LaTeX\ says: Hello world!
\end{document}

#### Warning

\documentclass{article}
\renewcommand{\familydefault}{\sfdefault}
\begin{document}
\emph{Hello world!}
\end{document}