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The ArrayBuffer
object is used to represent a generic, fixed-length raw binary data buffer.
It is an array of bytes, often referred to in other languages as a "byte array".
You cannot directly manipulate the contents of an ArrayBuffer
; instead, you create one of the typed array objects or a DataView
object which represents the buffer in a specific format, and use that to read and write the contents of the buffer.
The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.
Syntax
new ArrayBuffer(length)
Parameters
length
- The size, in bytes, of the array buffer to create.
Return value
A new ArrayBuffer
object of the specified size. Its contents are initialized to 0.
Exceptions
A RangeError
is thrown if the length
is larger than Number.MAX_SAFE_INTEGER
(>= 2 ** 53) or negative.
Description
The ArrayBuffer
constructor creates a new ArrayBuffer
of the given length in bytes.
Getting an array buffer from existing data
Properties
ArrayBuffer.length
- The
ArrayBuffer
constructor's length property whose value is 1. get ArrayBuffer[@@species]
- The constructor function that is used to create derived objects.
ArrayBuffer.prototype
- Allows the addition of properties to all
ArrayBuffer
objects.
Methods
ArrayBuffer.isView(arg)
- Returns
true
ifarg
is one of the ArrayBuffer views, such as typed array objects or aDataView
. Returnsfalse
otherwise. ArrayBuffer.transfer(oldBuffer [, newByteLength])
-
Returns a new
ArrayBuffer
whose contents are taken from theoldBuffer
's data and then is either truncated or zero-extended bynewByteLength
.
Instances
All ArrayBuffer
instances inherit from ArrayBuffer.prototype
.
Properties
- ArrayBuffer.prototype.constructor
- Specifies the function that creates an object's prototype. The initial value is the standard built-in
ArrayBuffer
constructor. ArrayBuffer.prototype.byteLength
Read only- The size, in bytes, of the array. This is established when the array is constructed and cannot be changed. Read only.
Methods
ArrayBuffer.prototype.slice()
- Returns a new
ArrayBuffer
whose contents are a copy of thisArrayBuffer
's bytes frombegin
, inclusive, up toend
, exclusive. If eitherbegin
orend
is negative, it refers to an index from the end of the array, as opposed to from the beginning.
ArrayBuffer.slice()
- Has the same functionality as
ArrayBuffer.prototype.slice()
.
Example
In this example, we create a 8-byte buffer with a Int32Array
view referring to the buffer:
var buffer = new ArrayBuffer(8); var view = new Int32Array(buffer);
Specifications
Specification | Status | Comment |
---|---|---|
Typed Array Specification | Obsolete | Superseded by ECMAScript 6. |
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'ArrayBuffer' in that specification. |
Standard | Initial definition in an ECMA standard. Specified that new is required. |
ECMAScript Latest Draft (ECMA-262) The definition of 'ArrayBuffer' in that specification. |
Draft |
Browser compatibility
Desktop | Mobile | Server | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
ArrayBuffer | Chrome Full support 7 | Edge Full support 12 | Firefox Full support 4 | IE Full support 10 | Opera Full support 11.6 | Safari Full support 5.1 | WebView Android Full support 4 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 12 | Safari iOS Full support 4.2 | Samsung Internet Android Full support Yes | nodejs Full support Yes |
byteLength | Chrome Full support 7 | Edge Full support 12 | Firefox Full support 4 | IE Full support 10 | Opera Full support 11.6 | Safari Full support 5.1 | WebView Android Full support 4 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 12 | Safari iOS Full support 4.2 | Samsung Internet Android Full support Yes | nodejs Full support Yes |
isView | Chrome Full support 32 | Edge Full support 12 | Firefox Full support 29 | IE Full support 11 | Opera Full support Yes | Safari Full support Yes | WebView Android Full support ≤37 | Chrome Android Full support 32 | Firefox Android Full support 29 | Opera Android Full support Yes | Safari iOS Full support Yes | Samsung Internet Android Full support 2.0 | nodejs Full support Yes |
ArrayBuffer() without new throws | Chrome Full support 7 | Edge Full support 14 | Firefox Full support 44 | IE No support No | Opera Full support Yes | Safari Full support 5.1 | WebView Android Full support ≤37 | Chrome Android Full support 18 | Firefox Android Full support 44 | Opera Android Full support Yes | Safari iOS Full support 5 | Samsung Internet Android Full support 1.0 | nodejs Full support 0.12 |
prototype | Chrome Full support 7 | Edge Full support 12 | Firefox Full support 4 | IE Full support 10 | Opera Full support 11.6 | Safari Full support 5.1 | WebView Android Full support 4 | Chrome Android Full support 18 | Firefox Android Full support 4 | Opera Android Full support 12 | Safari iOS Full support 4.2 | Samsung Internet Android Full support Yes | nodejs Full support Yes |
slice | Chrome Full support 17 | Edge Full support 12 | Firefox
Full support
12
| IE Full support 11 | Opera Full support Yes | Safari Full support 6 | WebView Android Full support ≤37 | Chrome Android Full support 18 | Firefox Android
Full support
14
| Opera Android Full support Yes | Safari iOS Full support 6 | Samsung Internet Android Full support 1.0 | nodejs Full support Yes |
transfer | Chrome No support No | Edge No support No | Firefox No support No | IE No support No | Opera No support No | Safari No support No | WebView Android No support No | Chrome Android No support No | Firefox Android No support No | Opera Android No support No | Safari iOS No support No | Samsung Internet Android No support No | nodejs No support No |
@@species | Chrome Full support 51 | Edge Full support 13 | Firefox Full support 48 | IE No support No | Opera Full support 38 | Safari ? | WebView Android Full support 51 | Chrome Android Full support 51 | Firefox Android Full support 48 | Opera Android Full support 41 | Safari iOS ? | Samsung Internet Android Full support 5.0 | nodejs
Full support
6.5.0
|
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- Experimental. Expect behavior to change in the future.
- Experimental. Expect behavior to change in the future.
- Non-standard. Expect poor cross-browser support.
- Non-standard. Expect poor cross-browser support.
- See implementation notes.
- See implementation notes.
- User must explicitly enable this feature.
- User must explicitly enable this feature.
Compatibility notes
Starting with ECMAScript 2015, ArrayBuffer
constructors require to be constructed with a new
operator. Calling an ArrayBuffer
constructor as a function without new
, will throw a TypeError
from now on.
var dv = ArrayBuffer(10); // TypeError: calling a builtin ArrayBuffer constructor // without new is forbidden
var dv = new ArrayBuffer(10);