byteLength 访问器属性表示以字节为单位的一个SharedArrayBuffer的长度。

Syntax

sab.byteLength

Description

The byteLength property is an accessor property whose set accessor function is undefined, meaning that you can only read this property. The value is established when the shared array is constructed and cannot be changed.

Examples

var sab = new SharedArrayBuffer(1024);
sab.byteLength; // 1024

Specifications

Specification	Status	Comment
ECMAScript Latest Draft (ECMA-262) SharedArrayBuffer.prototype.byteLength	Draft	Initial definition in ES2017.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile							Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Edge Mobile	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`byteLength`	Chrome Full support 68 Full support 68 No support 60 — 63 Notes Notes Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This was a temporary removal while mitigations were put in place.	Edge No support 16 — 17 Notes No support 16 — 17 Notes Notes Support was removed to mitigate speculative execution side-channel attacks (Windows blog).	Firefox Full support 57 Notes Disabled Full support 57 Notes Disabled Notes Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog). Disabled From version 57: this feature is behind the `javascript.options.shared_memory` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config. No support 55 — 57 No support 46 — 55 Disabled Disabled From version 46 until version 55 (exclusive): this feature is behind the `javascript.options.shared_memory` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	IE No support No	Opera No support No	Safari No support 10.1 — ?	WebView Android No support 60 — 63 Notes No support 60 — 63 Notes Notes Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.	Chrome Android No support 60 — 63 Notes No support 60 — 63 Notes Notes Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of speculative side-channel attacks. This is intended as a temporary measure until other mitigations are in place.	Edge Mobile ?	Firefox Android Full support 57 Notes Disabled Full support 57 Notes Disabled Notes Support was disabled by default to mitigate speculative execution side-channel attacks (Mozilla Security Blog). Disabled From version 57: this feature is behind the `javascript.options.shared_memory` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config. No support 55 — 57 No support 46 — 55 Disabled Disabled From version 46 until version 55 (exclusive): this feature is behind the `javascript.options.shared_memory` preference (needs to be set to `true`). To change preferences in Firefox, visit about:config.	Opera Android No support No	Safari iOS No support No	Samsung Internet Android No support No	nodejs Full support 8.10.0

Legend