Web/JavaScript/Reference/Global objects/TypedArray/slice

The slice() method returns a new typed array (with a new underlying buffer), that contains a copy of a portion of the original typed array. This method has the same algorithm as Array.prototype.slice(). TypedArray is one of the typed array types here.

Syntax

typedarray.slice([begin[, end]])

Parameters

begin Optional: Zero-based index at which to begin extraction.; A negative index can be used, indicating an offset from the end of the sequence. slice(-2) extracts the last two elements in the sequence.; If begin is undefined, slice begins from index 0.
end Optional: Zero-based index before which to end extraction. slice extracts up to but not including end.; For example, slice(1,4) extracts the second element through the fourth element (elements indexed 1, 2, and 3).; A negative index can be used, indicating an offset from the end of the sequence. slice(2,-1) extracts the third element through the second-to-last element in the sequence.; If end is omitted, slice extracts through the end of the sequence (typedarray.length).

Return value

A new typed array containing the extracted elements.

Description

The slice method does not alter. It returns a shallow copy of elements from the original typed array.

If a new element is added to either typed array, the other typed array is not affected.

Examples

Return a portion of an existing typed array

const uint8 = new Uint8Array([1,2,3]);
uint8.slice(1);   // Uint8Array [ 2, 3 ]
uint8.slice(2);   // Uint8Array [ 3 ]
uint8.slice(-2);  // Uint8Array [ 2, 3 ]
uint8.slice(0,1); // Uint8Array [ 1 ]

Polyfill

Since there is no global object with the name TypedArray, polyfilling must be done on an "as needed" basis.

if (!Uint8Array.prototype.slice) {
  Object.defineProperty(Uint8Array.prototype, 'slice', {
    value: function (begin, end)
     {
        return new Uint8Array(Array.prototype.slice.call(this, begin, end));
     }
  });
}

If you need to support truly obsolete JavaScript engines that don't support Object.defineProperty, it's best not to polyfill Array.prototype methods at all, as you can't make them non-enumerable.

Specifications

Specification
[(ECMA-262)The definition of '%TypedArray%.prototype.slice' in that specification.]

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`slice`	Chrome Full support 45	Edge Full support 14	Firefox Full support 38	IE No support No	Opera Full support 32	Safari Full support 10	WebView Android Full support 45	Chrome Android Full support 45	Firefox Android Full support 38	Opera Android Full support 32	Safari iOS Full support 10	Samsung Internet Android Full support 5.0	nodejs Full support 4.0.0

Legend

Full support: Full support
No support: No support