regExp.source
regExp.source
source
属性返回一个值为当前正则表达式对象的模式文本的字符串,该字符串不会包含正则字面量两边的斜杠以及任何的标志字符。
| RegExp.prototype.source
属性的属性特性 |
|:----|
| Writable | no |
| Enumerable | no |
| Configurable | yes |
示例
使用source
var regex = /fooBar/ig;
console.log(regex.source // "fooBar", doesn't contain /.../ and "ig".
清空正则表达式并转义
从ECMAScript 5开始,该source
属性不再为空的正则表达式返回一个空字符串。而是"(?:)"
返回字符串。另外,行终止符(例如“\ n”)现在被转义了。
new RegExp().source; // "(?:)"
new RegExp('\n').source === '\n'; // true, prior to ES5
new RegExp('\n').source === '\\n'; // true, starting with ES5
规范
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 | |
浏览器兼容性
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
"(?:)" for empty regexps | No support | ? | 38 (38) | ? | ? | (Yes) |
Escaping | ? | ? | 38 (38) | ? | ? | ? |
Prototype accessor property | ? | ? | 41 (41) | ? | ? | ? |
Feature | Android | Chrome for Android | Edge | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) | (Yes) |
"(?:)" for empty regexps | ? | ? | ? | 38.0 (38) | ? | ? | ? |
Escaping | ? | ? | ? | 38.0 (38) | ? | ? | ? |
Prototype accessor property | ? | ? | ? | 41.0 (41) | ? | ? | ? |