The join()
method joins all elements of an array into a string.
Syntax
str = arr.join([separator = ','])
Parameters
separator
- Optional. Specifies a string to separate each element of the array. The separator is converted to a string if necessary. If omitted, the array elements are separated with a comma. If
separator
is an empty string, all elements are joined without any characters in between them.
Description
The string conversions of all array elements are joined into one string. If an element is undefined
or null
, it is converted to the empty string.
Examples
Joining an array four different ways
The following example creates an array, a
, with three elements, then joins the array four times: using the default separator, then a comma and a space, then a plus and an empty string.
var a = ['Wind', 'Rain', 'Fire']; var myVar1 = a.join(); // assigns 'Wind,Rain,Fire' to myVar1 var myVar2 = a.join(', '); // assigns 'Wind, Rain, Fire' to myVar2 var myVar3 = a.join(' + '); // assigns 'Wind + Rain + Fire' to myVar3 var myVar4 = a.join(''); // assigns 'WindRainFire' to myVar4
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 1st Edition (ECMA-262) | Standard | Initial definition. Implemented in JavaScript 1.1. |
ECMAScript 5.1 (ECMA-262) The definition of 'Array.prototype.join' in that specification. |
Standard | |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Array.prototype.join' in that specification. |
Standard | |
ECMAScript 2017 Draft (ECMA-262) The definition of 'Array.prototype.join' in that specification. |
Draft |
Browser compatibility
Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 1.0 | 1.0 (1.7 or earlier) | 5.5 | (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
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Last updated by:
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