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.$+ is an alias for this property.
Description
The lastParen property is static, it is not a property of an individual regular expression object. Instead, you always use it as RegExp.lastParen or RegExp['$+'].
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 $+
var re = /(hi)/g;
re.test('hi there!');
RegExp.lastParen; // "hi"
RegExp['$+']; // "hi"
Specifications
| Specification |
|---|
| Legacy RegExp features in JavaScript |
Browser compatibility
| Desktop | Mobile | Server | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
RegExp.lastParen ($+) | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 5.5 | Opera Full support 10.5 | Safari Full support 3 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 11 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 | nodejs Full support Yes |
Legend
- Full support
- Full support
- Non-standard. Expect poor cross-browser support.
- Non-standard. Expect poor cross-browser support.
