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TypedArray.prototype.copyWithin()

The copyWithin() method of TypedArray instances shallow copies part of this typed array to another location in the same typed array and returns this typed array without modifying its length. This method has the same algorithm as Array.prototype.copyWithin().

Try it

Syntax

js
copyWithin(target, start)
copyWithin(target, start, end)

Parameters

target

Zero-based index at which to copy the sequence to, converted to an integer. This corresponds to where the element at start will be copied to, and all elements between start and end are copied to succeeding indices.

start

Zero-based index at which to start copying elements from, converted to an integer.

end Optional

Zero-based index at which to end copying elements from, converted to an integer. copyWithin() copies up to but not including end.

Return value

The modified typed array.

Description

See Array.prototype.copyWithin() for more details. This method is not generic and can only be called on typed array instances.

Examples

Using copyWithin()

js
const buffer = new ArrayBuffer(8);
const 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

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Opera Safari Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet WebView Android Deno Node.js
copyWithin 45 12 34 32 9.1 45 34 32 9.3 5.0 45 1.0 4.0.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/copyWithin