The concat() method combines the text of one or more strings and returns a new string.

Syntax

str.concat(string2[, string3, ..., stringN])

Parameters

string2...stringN
Strings to concatenate to this string.

Return value

A new string containing the combined text of the strings provided.

Description

The concat() function combines the text from one or more strings and returns a new string. Changes to the text in one string do not affect the other string.

Examples

Using concat()

The following example combines strings into a new string.

var hello = 'Hello, ';
console.log(hello.concat('Kevin', ' have a nice day.'));

/* Hello, Kevin have a nice day. */

Performance

It is strongly recommended that assignment operators (+, +=) are used instead of the concat() method. See this performance test.

Specifications

Specification Status Comment
ECMAScript 3rd Edition (ECMA-262) Standard Initial definition. Implemented in JavaScript 1.2.
ECMAScript 5.1 (ECMA-262)
The definition of 'String.prototype.concat' in that specification.
Standard  
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'String.prototype.concat' in that specification.
Standard  
ECMAScript 2017 Draft (ECMA-262)
The definition of 'String.prototype.concat' in that specification.
Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes) (Yes)

See also

Document Tags and Contributors

 Last updated by: eduardoboucas,