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) |