Commenting out single line and multi-line in LaTeX

It is a good habit to use comments in your LaTeX documents to explain what certain parts of your code are doing or to temporarily disable certain parts of your code while you are working on it.

In this tutorial, I will show you how to comment out single-line and multi-line in LaTeX. Let me see the topics.

• Single-line comment out (%)
• Multi-line command out (\iffalse and \fi)
• Commenting out using \begin{comment}...\end{comment}

Single-line comment out

In order to comment out a single line you can use % before that line. Anything on a line after the % symbol will be ignored by the compiler.

Also, you can select that line and press ctrl + / (for mac command + /) to comment out the line.

\documentclass{article}
\begin{document} 

This line will be visible in the output.\\
%This text will be ignored by the compiler.
This line also be visible in the output.

\end{document}

Output:

Multi-line comment out

If you want to comment out a block of text or multiple lines together. So, in this case, you can use \iffalse and \fi commands, anything you pass between these commands will be ignored by the compiler. Take a look.

\documentclass{article}
\begin{document} 

This line will be visible in the output.\\
%This text will be ignored by the compiler.
\iffalse
  This text will be ignored by the compiler.
  This text will also be ignored by the compiler.
\fi
This line also be visible in the output.

\end{document}

Output:

Use comment environment

You can also use the comment environment to comment out a large section of text or block of text. In order to use this environment you have to load comment or verbatim package. Anything you pass inside the comment environment will be ignored by the compiler.

\documentclass{article}
\usepackage{comment}
\begin{document} 

This line will be visible in the output.\\
%This text will be ignored by the compiler.
\begin{comment}
  This text will be ignored by the compiler.
  This text will also be ignored by the compiler.
\end{comment}
This line also be visible in the output.

\end{document}

Output: