ArrayBuffer

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.

* Some parts of this feature may have varying levels of support.

ArrayBuffer 物件是一種表示通用、固定大小的原始二進制資料緩衝。想要直接操作一個 ArrayBuffer 物件的內容是不可能的。若要讀寫該緩衝的內容則必須透過視圖,可以選擇建立一個 DataView 視圖物件或是一個限定其成員為某種型別的 TypedArray 視圖物件,它們皆能以特定的型別解讀、修改 ArrayBuffer

語法

js
new ArrayBuffer(length)

參數

length

要建立的緩衝陣列大小,以位元組(byte)計算。

回傳值

為一個新建立的指定大小 ArrayBuffer 物件,其內容皆初始化為 0。

Exceptions

A RangeError is thrown if the length is larger than Number.MAX_SAFE_INTEGER (>= 2 ** 53) or negative.

說明

The ArrayBuffer constructor creates a new ArrayBuffer of the given length in bytes.

從既有的資料取得 ArrayBuffer

屬性

ArrayBuffer.length

The ArrayBuffer constructor's length property whose value is 1.

ArrayBuffer[Symbol.species]

The constructor function that is used to create derived objects.

ArrayBuffer.prototype

Allows the addition of properties to all ArrayBuffer objects.

方法

ArrayBuffer.isView(arg)

Returns true if arg is one of the ArrayBuffer views, such as typed array objects or a DataView. Returns false otherwise.

ArrayBuffer.transfer(oldBuffer [, newByteLength]) 實驗性質

Returns a new ArrayBuffer whose contents are taken from the oldBuffer's data and then is either truncated or zero-extended by newByteLength.

ArrayBuffer 實例

所有的 ArrayBuffer 物件實例皆繼承自 ArrayBuffer.prototype.

屬性

ArrayBuffer.prototype[Symbol.toStringTag]

The initial value of the Symbol.toStringTag property is the string "ArrayBuffer". This property is used in Object.prototype.toString().

ArrayBuffer.prototype.byteLength

The read-only size, in bytes, of the ArrayBuffer. This is established when the array is constructed and cannot be changed.

方法

ArrayBuffer.prototype.slice()

Returns a new ArrayBuffer whose contents are a copy of this ArrayBuffer's bytes from begin (inclusive) up to end (exclusive). If either begin or end is negative, it refers to an index from the end of the array, as opposed to from the beginning.

範例

In this example, we create a 8-byte buffer with a Int32Array view referring to the buffer:

js
var buffer = new ArrayBuffer(8);
var view = new Int32Array(buffer);

規範

Specification
ECMAScript® 2025 Language Specification
# sec-arraybuffer-objects

瀏覽器相容性

Report problems with this compatibility data on GitHub
desktopmobileserver
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
Node.js
ArrayBuffer
[Symbol.species]
ArrayBuffer() constructor
maxByteLength option
byteLength
detached
isView
maxByteLength
resizable
resize
slice
transfer
transferToFixedLength

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
See implementation notes.

相容性備註

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.

js
var dv = ArrayBuffer(10);
// TypeError: calling a builtin ArrayBuffer constructor
// without new is forbidden
js
var dv = new ArrayBuffer(10);

參見