Return to Variables_in_Scripts.tex CVS log

Up to [LON-CAPA] / loncom / html / adm / help / tex

This commit implements the .tex-based online help system in LON-CAPA. It
may be necessary to manually run loncom/build/help_graphics_converter.pl
and doc/help/rebuildLabelHash.pl after a cvs update, and
loncapa_apache.conf may need to be manually copied to /etc. (The
loncapafiles.lpml has been updated.)

After merging this, the URL http://[loncapahost]/adm/help/Foils.hlp
should display a help file.

Also, some *very* out-of-date files have been removed from the /doc
directory.

Variables can be used later in the same script. For instance, we can add
another line below the \texttt{\$variable} line as such:

\begin{lyxcode}
\$variable2~=~\$variable~+~2;
\end{lyxcode}

Now there is a variable called \texttt{\$variable2} with the the number {}``5''
as its value. 

Variables can also be used in \emph{strings}\index{strings}, which are a
sequence of letters. The underlying language of the script, Perl, has a very
large number of ways of using variables in strings, but the easiest and most
common way is to use normal double-quotes and just spell out the name of
the variable you want to use in the string, like this:

\begin{lyxcode}
\$stringVar~=~{}``I~have~a~variable~with~the~value~\$variable.''
\end{lyxcode}

This will put the string {}``I have a variable with the value 3.'' into
the variable named {}``stringVar''.