How to write programming code containing the ' character in latex?

I am trying to write programming code in latex using the verbatim environment, but when I write

  \begin{verbatim}
     char ch = 'x';
  \end{verbatim}

the开发者_开发百科n the ' -characters around x are displayed incorrectly (they look "curly"). How can I fix this problem?

Load the upquote package to fix this issue in verbatim mode.

If you want straight quotes in monospaced text mode (e.g., \texttt{...}), or indeed in any other font, then you can use the \textquotesingle command defined in the textcomp package:

\documentclass{article}
\usepackage{upquote,textcomp}
\begin{document}
\newcommand\upquote[1]{\textquotesingle#1\textquotesingle}
\verb|'c'| \texttt{\upquote{h}}
\textsf{\upquote{h}} \upquote{h}
\end{document}

This will work well for fonts in any encoding rather than depending on a specific glyph slot (such as \char13 in the default OT1 encoding).

Adding \usepackage{upquote} to my preamble was sufficient.

Perhaps older versions of LaTeX or upquote required more work.

I have

What is wrong?

New

If you want to get something like this

write

\makeatletter
\let \@sverbatim \@verbatim
\def \@verbatim {\@sverbatim \verbatimplus}
{\catcode`'=13 \gdef \verbatimplus{\catcode`'=13 \chardef '=13 }} 
\makeatother

For displaying source code, you might consider using the listings package; it is quite powerful and offers an option to display “straight” quotation marks.

If you're seeing curly single right quotes in a verbatim environment, then the single right quote in your typewriter font is curly, and that's the correct one to use for what you're doing (which I assume is displaying some C code).

\textsf{``} and \textsf{''} come pretty close to straight quotes. No need for using any special packages.

This is what I got from another source, and this works.

Use `` to start the double quotes (this symbol is below ~ symbol on our keyboard)

Use '' to close the double quotes (this symbol is below the " symbol on our keyboard)

So, `` quote double, unquote double''

Same goes for single quotes, `quote single, unquote single'