Uint16Array() constructor

The Uint16Array() typed array constructor creates an array of 16-bit unsigned integers in the platform byte order.

Syntax

new Uint16Array(); // new in ES2017
new Uint16Array(length);
new Uint16Array(typedArray);
new Uint16Array(object);

new Uint16Array(buffer);
new Uint16Array(buffer, byteOffset);
new Uint16Array(buffer, byteOffset, length);

Parameters

length

When called with a length argument, an internal array buffer is created in memory, of size length multiplied by BYTES_PER_ELEMENT bytes, containing zeros.

typedArray

When called with a typedArray argument, which can be an object of any of the non-bigint typed-array types (such as Int32Array), the typedArray gets copied into a new typed array. Each value in typedArray is converted to the corresponding type of the constructor before being copied into the new array. The length of the new typed array will be same as the length of the typedArray argument.

object

When called with an object argument, a new typed array is created as if by the TypedArray.from() method.

buffer, byteOffset, length

When called with a buffer, and optionally a byteOffset and a length argument, a new typed array view is created that views the specified ArrayBuffer. The byteOffset and length parameters specify the memory range that will be exposed by the typed array view. If both are omitted, all of buffer is viewed; if only length is omitted, the remainder of buffer is viewed.

Examples

Different ways to create a Uint16Array

// From a length
const uint16 = new Uint16Array(2);
uint16[0] = 42;
console.log(uint16[0]); // 42
console.log(uint16.length); // 2
console.log(uint16.BYTES_PER_ELEMENT); // 2

// From an array
const x = new Uint16Array([21, 31]);
console.log(x[1]); // 31

// From another TypedArray
const y = new Uint16Array(x);
console.log(y[0]); // 21

// From an ArrayBuffer
const buffer = new ArrayBuffer(16);
const z = new Uint16Array(buffer, 2, 4);
console.log(z.byteOffset); // 2

// From an iterable
const iterable = function*() { yield* [1, 2, 3]; }();
const uint16FromIterable = new Uint16Array(iterable);
console.log(uint16FromIterable);
// Uint16Array [1, 2, 3]

Specifications

Specification
ECMAScript Language Specification
# sec-typedarray-constructors

Browser compatibility

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Compatibility notes

Starting with ECMAScript 2015, Uint16Array constructors require to be constructed with a new operator. Calling a Uint16Array constructor as a function without new, will throw a TypeError from now on. 

const dv = Uint16Array([1, 2, 3]);
// TypeError: calling a builtin Uint8ClampedArray constructor
// without new is forbidden

const dv = new Uint16Array([1, 2, 3]);

See also