The concat()
method concatenates the string arguments to the calling string and returns a new string.
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Syntax
str.concat(str2 [, ...strN])
Parameters
str2 [, ...strN]
- Strings to concatenate to
str
.
Return value
A new string containing the combined text of the strings provided.
Description
The concat()
function concatenates the string arguments to the calling string and returns a new string. Changes to the original string or the returned string don't affect the other.
If the arguments are not of the type string, they are converted to string values before concatenating.
Performance
It is strongly recommended that the assignment operators (+
, +=
) are used instead of the concat()
method.
Examples
Using concat()
The following example combines strings into a new string.
let hello = 'Hello, ' console.log(hello.concat('Kevin', '. Have a nice day.')) // Hello, Kevin. Have a nice day. let greetList = ['Hello', ' ', 'Venkat', '!'] "".concat(...greetList) // "Hello Venkat!" "".concat({}) // [object Object] "".concat([]) // "" "".concat(null) // "null" "".concat(true) // "true" "".concat(4, 5) // "45"
Specifications
Specification |
---|
ECMAScript (ECMA-262) The definition of 'String.prototype.concat' in that specification. |
Browser compatibility
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Desktop | Mobile | Server | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
concat | Chrome Full support 1 | Edge Full support 12 | Firefox Full support 1 | IE Full support 4 | Opera Full support 4 | Safari Full support 1 | WebView Android Full support 1 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 10.1 | Safari iOS Full support 1 | Samsung Internet Android Full support 1.0 | nodejs Full support 0.1.100 |
Legend
- Full support
- Full support