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 |
| Desktop | ||||||
|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | |
| Basic support | Yes | Yes | 1 | Yes | Yes | Yes |
| Prototype accessor property (ES2015) | Yes | ? | 41 | ? | Yes | Yes |
| Escaping | ? | ? | 38 | ? | ? | ? |
| "(?:)" for empty regexps | Yes | ? | 38 | ? | ? | Yes |
| Mobile | |||||||
|---|---|---|---|---|---|---|---|
| Android webview | Chrome for Android | Edge Mobile | Firefox for Android | Opera for Android | iOS Safari | Samsung Internet | |
| Basic support | Yes | Yes | Yes | 4 | Yes | Yes | Yes |
| Prototype accessor property (ES2015) | Yes | Yes | ? | 41 | Yes | Yes | Yes |
| Escaping | ? | ? | ? | 38 | ? | ? | ? |
| "(?:)" for empty regexps | ? | ? | ? | 38 | ? | ? | ? |
| Server | |
|---|---|
| Node.js | |
| Basic support | Yes |
| Prototype accessor property (ES2015) | Yes |
| Escaping | ? |
| "(?:)" for empty regexps | ? |
© 2005–2018 Mozilla Developer Network and individual 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/source