Uint8Array
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
typed array represents an array of 8-bit unsigned integers. The contents are initialized to 0
unless initialization data is explicitly provided. Once established, you can reference elements in the array using the object's methods, or using standard array index syntax (that is, using bracket notation).
Uint8Array
is a subclass of the hidden TypedArray
class.
Constructor
Uint8Array()
-
Creates a new
Uint8Array
object.
Static properties
Also inherits static properties from its parent TypedArray
.
Uint8Array.BYTES_PER_ELEMENT
-
Returns a number value of the element size.
1
in the case ofUint8Array
.
Static methods
Inherits static methods from its parent TypedArray
.
Instance properties
Also inherits instance properties from its parent TypedArray
.
These properties are defined on Uint8Array.prototype
and shared by all Uint8Array
instances.
Uint8Array.prototype.BYTES_PER_ELEMENT
-
Returns a number value of the element size.
1
in the case of aUint8Array
. Uint8Array.prototype.constructor
-
The constructor function that created the instance object. For
Uint8Array
instances, the initial value is theUint8Array
constructor.
Instance methods
Inherits instance methods from its parent TypedArray
.
Examples
Different ways to create a Uint8Array
// 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 Language Specification # table-49 |
Browser compatibility
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