typedArray.subarray

The subarray() method returns a new TypedArray on the same ArrayBuffer store and with the same element types as for this TypedArray object. The begin offset is inclusive and the end offset is exclusive. TypedArray is one of the typed array types.

Syntax

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

Parameters

begin Optional

Element to begin at. The offset is inclusive. The whole array will be cloned if this value is not specified.

end Optional

Element to end at. The offset is exclusive. If not specified, all elements from the one specified by begin to the end of the array are included in the new view.

Return value

A new TypedArray object.

Description

The range specified by begin and end is clamped to the valid index range for the current array; if the computed length of the new array would be negative, it's clamped to zero. If either begin or end is negative, it refers to an index from the end of the array instead of from the beginning.

Also note that this is creating a new view on the existing buffer; changes to the new object's contents will impact the original object and vice versa.

Examples

Using the subarray method

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 ]

var sub = uint8.subarray(0,4);

console.log(sub);   // Uint8Array [ 1, 2, 3, 0 ]

Specifications

Specification	Status	Comment
Typed Array Specification	Obsolete	Superseded by ECMAScript 6.
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'TypedArray.prototype.subarray' in that specification.	Standard	Initial definition in an ECMA standard.
ECMAScript 2017 Draft (ECMA-262) The definition of 'TypedArray.prototype.subarray' in that specification.	Draft

Browser compatibility

See also

• JavaScript typed arrays
• TypedArray
• ArrayBuffer