# Conditional text lines latex document

I am writing an exam for a course I am teaching. I want to be able to easily compile a version of the document with solutions and one without solutions. Below a minimal working example:

  \documentclass[12pt]{article}
\usepackage{amssymb}
\usepackage{amsmath}
\begin{document}
\begin{enumerate}
\item{[1 point] Two plus two is equal to what?}
\begin{footnotesize}
\begin{itemize}
\item  $2+2 = 4$
\end{itemize}
\end{footnotesize}
\item{[1 point] How many months are there in a year?}
\begin{footnotesize}
\begin{itemize}
\item There are 12 months in the year
\end{itemize}
\end{footnotesize}
\end{enumerate}
\end{document}


What I want is a way of automatically commenting out the solution lines. Such as an if statement. If solution = true, then print the solution of the exam. Else do not print.

• Without conditional nor boolean variables, to hide or show every \solution{<whatever>} in the document you can switch between some like \def\solution{#1} and \def\solution{} in the preamble, so you need only type/remove #1, or have both definitions and just inactivate one with a % before. – Fran May 4 at 13:15
• That would work for me but I am unsure how to implement it. – phdstudent May 4 at 13:20

Use the comment package https://ctan.org/pkg/comment?lang=en

Toggle whether you want to show solutions by commenting out one of the \includecomment and \excludecomment lines, and uncommenting the other.

\documentclass[12pt]{article}
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{comment}

%\includecomment{solution}
\excludecomment{solution}

\begin{document}
\begin{enumerate}
\item{[1 point] Two plus two is equal to what?}
\begin{solution}
\begin{footnotesize}
\begin{itemize}
\item  $2+2 = 4$
\end{itemize}
\end{footnotesize}
\end{solution}
\item{[1 point] How many months are there in a year?}
\begin{solution}
\begin{footnotesize}
\begin{itemize}
\item There are 12 months in the year
\end{itemize}
\end{footnotesize}
\end{solution}
\end{enumerate}
\end{document}


### Option 2: use the exam class

It looks like you are writing a quiz/exam. I would highly encourage you to look into the exam class https://ctan.org/pkg/exam?lang=en

The class includes features like automatically tallying the total number of points, hiding/unhiding solutions, and much more.