JavaScript Regular expressions RegExp Flags


There are several flags you can specify to alter the RegEx behaviour. Flags may be appended to the end of a regex literal, such as specifying gi in /test/gi, or they may be specified as the second argument to the RegExp constructor, as in new RegExp('test', 'gi').

g - Global. Finds all matches instead of stopping after the first.

i - Ignore case. /[a-z]/i is equivalent to /[a-zA-Z]/.

m - Multiline. ^ and $ match the beginning and end of each line respectively treating \n and \r as delimiters instead of simply the beginning and end of the entire string.


u - Unicode. If this flag is not supported you must match specific Unicode characters with \uXXXX where XXXX is the character's value in hexadecimal.

y - Finds all consecutive/adjacent matches.