Regular Expressions Cookbook, 2nd Edition

Single-Line Comments

Problem

You want to match a comment that starts with // and runs until the end of the line.

Solution

//.*

Regex options: None

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

Discussion

The forward slash has no special meaning in regular expressions, so we can easily match the start of the comment with ‹//›. Some programming languages use forward slashes to delimit regular expressions. When you use this regular expression in your code, you may need to escape the forward slashes as explained in Recipe 3.1.

‹.*› simply matches everything up to the end of the line. We don’t need to add anything to the regular expression to make it stop at the end of a line. Just make sure the option “dot matches line breaks” is turned off when using this regular expression.

See Also

Recipe 2.4 explains that the dot matches any character.