RegExp.prototype.toString()

The toString() method returns a string representing the regular expression.

Syntax

regexObj.toString();

Return value

A string representing the given object.

Description

The RegExp object overrides the toString() method of the Object object; it does not inherit Object.prototype.toString(). For RegExp objects, the toString() method returns a string representation of the regular expression.

Examples

Using toString()

The following example displays the string value of a RegExp object:

var myExp = new RegExp('a+b+c');
console.log(myExp.toString());  // logs '/a+b+c/'

var foo = new RegExp('bar', 'g');
console.log(foo.toString());    // logs '/bar/g'

Empty regular expressions and escaping

Starting with ECMAScript 5, an empty regular expression returns the string "/(?:)/" and line terminators such as "\n" are escaped:

new RegExp().toString(); // "/(?:)/"

new RegExp('\n').toString() === '/\n/';  // true, prior to ES5
new RegExp('\n').toString() === '/\\n/'; // true, starting with ES5

Specifications

Specification Status Comment
ECMAScript 3rd Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.1.
ECMAScript 5.1 (ECMA-262)
The definition of 'RegExp.prototype.toString' in that specification.
Standard Added definition for escaping behavior and "(?:)" for empty regular expressions.
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'RegExp.prototype.toString' in that specification.
Standard  
ECMAScript Latest Draft (ECMA-262)
The definition of 'RegExp.prototype.toString' in that specification.
Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
toStringChrome Full support 1Edge Full support 12Firefox Full support 1IE Full support 4Opera Full support YesSafari Full support YesWebView Android Full support 1Chrome Android Full support 18Firefox Android Full support 4Opera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support 1.0nodejs Full support Yes
EscapingChrome Full support 73Edge Full support 12Firefox Full support 38IE Full support 9Opera Full support 60Safari Full support YesWebView Android Full support 73Chrome Android Full support 73Firefox Android Full support 38Opera Android Full support 52Safari iOS Full support YesSamsung Internet Android No support Nonodejs Full support Yes

Legend

Full support  
Full support
No support  
No support

See also