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regExp.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

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
toString 1 12 1 4 5 1
Escaping 73 12 38 9 60 6
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
toString 1 18 4 10.1 1 1.0
Escaping 73 73 38 52 6 No
Server
Node.js
toString 0.1.100
Escaping 12.0.0

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/toString