RegExp.lastParen ($+)

Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

The non-standard lastParen property is a static and read-only property of regular expressions that contains the last parenthesized substring match, if any. RegExp.$+ is an alias for this property.

Syntax

JavaScript
<var>RegExp</var>.lastParen
RegExp['$+']

Description

The lastParen property is static, it is not a property of an individual regular expression object. Instead, you always use it as RegExp.lastParen or RegExp['$+'].

The value of the lastParen property is read-only and modified whenever a successful match is made.

You can not use the shorthand alias with the dot property accessor (RegExp.$+), because the parser expects an expression with "+" in that case and a SyntaxError is thrown. Use the bracket notation for property access.

Examples

Using lastParen and $+

JavaScript
var re = /(hi)/g;
re.test("hi there!");
RegExp.lastParen; // "hi"
RegExp['$+'];     // "hi"

Specifications

Non-standard. Not part of any current specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/javascript/reference/global_objects/regexp/lastparen

JavaScript Property Read-only Reference RegExp Regular Expressions