The copyWithin() method copies the sequence of array elements within the array to the position starting at target. The copy is taken from the index positions of the second and third arguments start and end. The end argument is optional and defaults to the length of the array. This method has the same algorithm as Array.prototype.copyWithin. TypedArray is one of the typed array types here.
Syntax
typedarray.copyWithin(target, start[, end = this.length])
Parameters
target- Target start index position where to copy the elements to.
start- Source start index position where to start copying elements from.
end Optional- Optional. Source end index position where to end copying elements from.
Return value
The modified array.
Description
See Array.prototype.copyWithin for more details.
This method replaces the experimental TypedArray.prototype.move().
Examples
var buffer = new ArrayBuffer(8); var uint8 = new Uint8Array(buffer); uint8.set([1,2,3]); console.log(uint8); // Uint8Array [ 1, 2, 3, 0, 0, 0, 0, 0 ] uint8.copyWithin(3,0,3); console.log(uint8); // Uint8Array [ 1, 2, 3, 1, 2, 3, 0, 0 ]
Specifications
| Specification | Status | Comment |
|---|---|---|
| ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'TypedArray.prototype.copyWithin' in that specification. |
Standard | Initial definition. |
| ECMAScript 2017 Draft (ECMA-262) The definition of 'TypedArray.prototype.copyWithin' in that specification. |
Draft |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 45.0 | 34 (34) | No support |
36.0 |
No support |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | No support | No support | 34.0 (34) | No support | No support | No support |