JavaScript Typed Array Reference

Example

const myArr = new Int8Array(10);

JavaScript Typed Arrays

In Javascript, a typed array is an array-like buffer of binary data.

There is no JavaScript property or object named TypedArray, but properties and methods can be used with typed array objects:

Typed Array Objects

Object	Data Type	Range	Try it
Int8Array	Signed integer (byte)	-128/127	Try it »
Uint8Array	Unsigned integer (octet)	0/255	Try it »
Uint8ClampedArray	Unsigned integer (octet)	0/255	Try it »
Int16Array	Short integer	-32768/32767	Try it »
Uint16Array	Unsigned short integer	0/65535	Try it »
Int32Array	Signed long integer	-2³¹/2³¹-1	Try it »
Uint32Array	Unsigned long integer	0/2³²	Try it »
Float32Array	Float - 7 significant digits	1.2x10^-38/3.4x10³⁸	Try it »
Float64Array	Double - 16 significant digits	5.0x10^-324/1.8x10³⁰⁸	Try it »
BigInt64Array	Big signed integer	-2⁶³/2⁶³-1	Try it »
BigUint64Array	Big unsigned integer	0/2⁶⁴	Try it »

Note

Typed arrays are not arrays.

isArray() on a typed array returns false.

Many array methods (like push and pop) are not supported by typed arrays.

Typed arrays are array-like objects for storing binary data in memory.

Typed Array Methods and Properties

Method / Property	Description	Try it
BYTES_PER_ELEMENT	Property to count the number of bytes used to store one element	Try it »
fill()	Fill all elements with a value	Try it »
find()	Returns the first element that satisfies a condition	Try it »
name	Returns the name of the typed array	Try it »
of()	Method to create a typed array from an array	Try it »
some()	Reurns true if one element satisfies a condition	Try it »

Uint8Array vs Uint8ClampedArray

The difference between an Uint8Array and an Uint8ClampedArray is how values are added.

If you set one element in an Uint8ClampedArray to a value outside the 0-255 range, it will default to 0 or 255.

A typed array will just take the first 8 bits of the value.

Typed Array Benefits

Typed arrays provide a way to handle binary data as efficiently as arrays work in C.

Typed arrays are raw memory, so JavaScript can pass them directly to any function without converting the data to another representation.

Typed arrays are serously faster than normal arrays, for passing data to functions that can use raw binary data (Computer Games, WebGL, Canvas, File APIs, Media APIs).

Browser APIs Supporting Typed Arrays

Fetch API Example

fetch(url)
.then(request => request.arrayBuffer())
.then(arrayBuffer =>...);

Canvas Example

const canvas = document.getElementById('my_canvas');
const context = canvas.getContext('2d');
const imageData = context.getImageData(0, 0, canvas.width, canvas.height);
const uint8ClampedArray = imageData.data;

Browser Support

typedArray is an ECMAScript6 (ES6) feature.

ES6 (JavaScript 2015) is supported in all modern browsers:


Chrome	Edge	Firefox	Safari	Opera
Yes	Yes	Yes	Yes	Yes

typedArray is not supported in Internet Explorer 11 (or earlier).

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