The source
property returns a String
containing the source text of the regexp object, and it doesn't contain the two forward slashes on both sides and any flags.
Property attributes of RegExp.prototype.source
| |
---|---|
Writable | no |
Enumerable | no |
Configurable | yes |
source
var regex = /fooBar/ig; console.log(regex.source); // "fooBar", doesn't contain /.../ and "ig".
Starting with ECMAScript 5, the source
property no longer returns an empty string for empty regular expressions. Instead, the string "(?:)"
is returned. In addition, line terminators (such as "\n") are escaped now.
new RegExp().source; // "(?:)" new RegExp('\n').source === '\n'; // true, prior to ES5 new RegExp('\n').source === '\\n'; // true, starting with ES5
Specification | Status | Comment |
---|---|---|
ECMAScript 3rd Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.2. JavaScript 1.5: source is a property of a RegExp instance, not the RegExp object. |
ECMAScript 5.1 (ECMA-262) The definition of 'RegExp.prototype.source' in that specification. | Standard | The source property for empty regular expressions now returns "(?:)" instead of an empty string. A definition for the escaping behavior has been added. |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'RegExp.prototype.source' in that specification. | Standard |
source is now a prototype accessor property rather than an instance's own data property. |
ECMAScript Latest Draft (ECMA-262) The definition of 'RegExp.prototype.source' in that specification. | Draft |
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | Yes | Yes | Yes | Yes | Yes | Yes |
Prototype accessor property (ES2015) | Yes | ? | 41 | ? | Yes | Yes |
Escaping | ? | ? | 38 | ? | ? | ? |
"(?:)" for empty regexps | Yes | ? | 38 | ? | ? | Yes |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | Opera Android | iOS Safari | Samsung Internet |
---|---|---|---|---|---|---|---|
Basic support | Yes | Yes | Yes | Yes | Yes | Yes | ? |
Prototype accessor property (ES2015) | Yes | Yes | ? | 41 | Yes | Yes | ? |
Escaping | ? | ? | ? | 38 | ? | ? | ? |
"(?:)" for empty regexps | ? | ? | ? | 38 | ? | ? | ? |
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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/source