Array.unshift Redirect 1


The unshift() method adds one or more elements to the beginning of an array and returns the new length of the array.


arr.unshift(element1, ..., elementN) 


element1, ..., elementN
The elements to add to the front of the array.


The new length property of the object upon which the method was called.


The unshift method inserts the given values to the beginning of an array-like object.

unshift is intentionally generic; this method can be called or applied to objects resembling arrays. Objects which do not contain a length property reflecting the last in a series of consecutive, zero-based numerical properties may not behave in any meaningful manner.


var arr = [1, 2];

arr.unshift(0); // result of call is 3, the new array length
// arr is [0, 1, 2]

arr.unshift(-2, -1); // = 5
// arr is [-2, -1, 0, 1, 2]

arr.unshift( [-3] );
// arr is [[-3], -2, -1, 0, 1, 2]


Specification Status Comment
ECMAScript 3rd Edition Standard Initial definition.
Implemented in JavaScript 1.2
ECMAScript Language Specification 5.1th Edition (ECMA-262) Standard  
ECMAScript Language Specification 6th Edition (ECMA-262) 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

Document Tags and Contributors

 Last updated by: Sheppy,