RegExp.prototype.source

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

Examples

Using source

var regex = /fooBar/ig;

console.log(regex.source); // "fooBar", doesn't contain /.../ and "ig".

Empty regular expressions and escaping

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

Specifications

Specification
ECMAScript Latest Draft (ECMA-262)
The definition of 'RegExp.prototype.source' in that specification.

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
sourceChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 4Opera Full support YesSafari Full support 1WebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support YesSafari iOS Full support 1Samsung Internet Android Full support 1.0nodejs Full support Yes
"(?:)" for empty regexpsChrome Full support 6Edge Full support 12Firefox Full support 38IE No support NoOpera Full support 15Safari Full support 5WebView Android Full support ≤37Chrome Android Full support 18Firefox Android Full support 38Opera Android Full support 14Safari iOS Full support 4.2Samsung Internet Android Full support 1.0nodejs ?
EscapingChrome Full support 73Edge Full support 12Firefox Full support 38IE Full support 10Opera Full support 60Safari Full support 6WebView Android Full support 73Chrome Android Full support 73Firefox Android Full support 38Opera Android Full support 52Safari iOS Full support 6Samsung Internet Android No support Nonodejs ?
Prototype accessor property (ES2015)Chrome Full support 48Edge Full support 12Firefox Full support 41IE Full support 4Opera Full support 35Safari Full support 1.3WebView Android Full support 48Chrome Android Full support 48Firefox Android Full support 41Opera Android Full support 35Safari iOS Full support 1Samsung Internet Android Full support 5.0nodejs Full support Yes

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown

See also

Related Topics
  1. Standard built-in objects
  2. RegExp
  3. Properties
    1. RegExp.$1-$9
    2. RegExp.input ($_)
    3. RegExp.lastMatch ($&)
    4. RegExp.lastParen ($+)
    5. RegExp.leftContext ($`)
    6. RegExp.prototype.dotAll
    7. RegExp.prototype.flags
    8. RegExp.prototype.global
    9. RegExp.prototype.ignoreCase
    10. RegExp.prototype.multiline
    11. RegExp.prototype.source
    12. RegExp.prototype.sticky
    13. RegExp.prototype.unicode
    14. RegExp.rightContext ($')
    15. get RegExp[@@species]
    16. regexp.lastIndex
  4. Methods
    1. RegExp.prototype.compile()
    2. RegExp.prototype.exec()
    3. RegExp.prototype.test()
    4. RegExp.prototype.toSource()
    5. RegExp.prototype.toString()
    6. RegExp.prototype[@@matchAll]()
    7. RegExp.prototype[@@match]()
    8. RegExp.prototype[@@replace]()
    9. RegExp.prototype[@@search]()
    10. RegExp.prototype[@@split]()
  5. Inheritance:
  6. Function
  7. Properties
    1. Function.arguments
    2. Function.arity
    3. Function.caller
    4. Function.displayName
    5. Function.length
    6. Function.name
  8. Methods
    1. Function.prototype.apply()
    2. Function.prototype.bind()
    3. Function.prototype.call()
    4. Function.prototype.isGenerator()
    5. Function.prototype.toSource()
    6. Function.prototype.toString()
  9. Object
  10. Properties
    1. Object.prototype.__count__
    2. Object.prototype.__noSuchMethod__
    3. Object.prototype.__parent__
    4. Object.prototype.__proto__
    5. Object.prototype.constructor
  11. Methods
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.unwatch()
    12. Object.prototype.valueOf()
    13. Object.prototype.watch()
    14. Object.setPrototypeOf()