Uint8Array() constructor
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
The Uint8Array()
constructor creates Uint8Array
objects. The contents are initialized to 0
unless initialization data is explicitly provided.
Syntax
Parameters
See TypedArray
.
Exceptions
See TypedArray
.
Examples
Different ways to create a Uint8Array
js
// From a length
const uint8 = new Uint8Array(2);
uint8[0] = 42;
console.log(uint8[0]); // 42
console.log(uint8.length); // 2
console.log(uint8.BYTES_PER_ELEMENT); // 1
// From an array
const x = new Uint8Array([21, 31]);
console.log(x[1]); // 31
// From another TypedArray
const y = new Uint8Array(x);
console.log(y[0]); // 21
// From an ArrayBuffer
const buffer = new ArrayBuffer(8);
const z = new Uint8Array(buffer, 1, 4);
console.log(z.byteOffset); // 1
// From an iterable
const iterable = (function* () {
yield* [1, 2, 3];
})();
const uint8FromIterable = new Uint8Array(iterable);
console.log(uint8FromIterable);
// Uint8Array [1, 2, 3]
Specifications
Specification |
---|
ECMAScript® 2025 Language Specification # sec-typedarray-constructors |
Browser compatibility
Report problems with this compatibility data on GitHubdesktop | mobile | server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Uint8Array() constructor | ||||||||||||||
Constructor without parameters | ||||||||||||||
new Uint8Array(iterable) |
Legend
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- Full support
- Full support
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