TypedArray.prototype.length

length访问器属性表示类型化数组的长度（元素数）。

语法

typedarray.length

描述

length 是一个访问器属性，它的 set 访问器函数是undefined，意思是你只能够读取这个属性。它的值在TypedArray构造时建立，不能被修改。如果 TypedArray 没有指定byteOffset 或者 length，会返回所引用的ArrayBuffer 的length。TypedArray 是这里的 TypedArray 对象之一。

示例

使用length 属性

var buffer = new ArrayBuffer(8);

var uint8 = new Uint8Array(buffer);
uint8.length; // 8 (符合 buffer 的 length)

var uint8 = new Uint8Array(buffer, 1, 5);
uint8.length; // 5 (在 Uint8Array 构造时指定)

var uint8 = new Uint8Array(buffer, 2);
uint8.length; // 6 (根据被构造的 Uint8Array 的 offset)

规范

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
TypedArray.prototype.length		 Standard 初始定义
ECMAScript Latest Draft (ECMA-262)
TypedArray.prototype.length		 Draft  

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 7.0 4.0 (2) 10 11.6 5.1
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support 4.0 (Yes) 4.0 (2) 10 11.6 4.2

另见

  1. JavaScript 标准库
  2. TypedArray
  3. 属性
    1. TypedArray.BYTES_PER_ELEMENT
    2. TypedArray.name
    3. TypedArray.prototype
    4. TypedArray.prototype.buffer
    5. TypedArray.prototype.byteLength
    6. TypedArray.prototype.byteOffset
    7. TypedArray.prototype.length
    8. get TypedArray[@@species]
  4. 方法
    1. TypedArray.from()
    2. TypedArray.of()
    3. TypedArray.prototype.copyWithin()
    4. TypedArray.prototype.entries()
    5. TypedArray.prototype.every()
    6. TypedArray.prototype.fill()
    7. TypedArray.prototype.filter()
    8. TypedArray.prototype.find()
    9. TypedArray.prototype.findIndex()
    10. TypedArray.prototype.forEach()
    11. TypedArray.prototype.includes()
    12. TypedArray.prototype.indexOf()
    13. TypedArray.prototype.join()
    14. TypedArray.prototype.keys()
    15. TypedArray.prototype.lastIndexOf()
    16. TypedArray.prototype.map()
    17. TypedArray.prototype.move()
    18. TypedArray.prototype.reduce()
    19. TypedArray.prototype.reduceRight()
    20. TypedArray.prototype.reverse()
    21. TypedArray.prototype.set()
    22. TypedArray.prototype.slice()
    23. TypedArray.prototype.some()
    24. TypedArray.prototype.sort()
    25. TypedArray.prototype.subarray()
    26. TypedArray.prototype.toLocaleString()
    27. TypedArray.prototype.toString()
    28. TypedArray.prototype.values()
    29. TypedArray.prototype[@@iterator]()
  5. Related pages:
  6. Int8Array
  7. Uint8Array
  8. Uint8ClampedArray
  9. Int16Array
  10. Uint16Array
  11. Int32Array
  12. Uint32Array
  13. Float32Array
  14. Float64Array
  15. 继承
  16. Function
  17. 属性
    1. Function.arguments
    2. Function.arity
    3. Function.caller
    4. Function.displayName
    5. Function.length
    6. Function.prototype
    7. Function.name
  18. 方法
    1. Function.prototype.apply()
    2. Function.prototype.bind()
    3. Function.prototype.call()
    4. Function.prototype.isGenerator()
    5. Function.prototype.toSource()
    6. Function.prototype.toString()
  19. Object
  20. 属性
    1. Object.prototype.__count__
    2. Object.prototype.__noSuchMethod__
    3. Object.prototype.__parent__
    4. Object.prototype.__proto__
    5. Object.prototype.constructor
  21. 方法
    1. Object.prototype.__defineGetter__()
    2. Object.prototype.__defineSetter__()
    3. Object.prototype.__lookupGetter__()
    4. Object.prototype.__lookupSetter__()
    5. Object.prototype.hasOwnProperty()
    6. Object.prototype.isPrototypeOf()
    7. Object.prototype.propertyIsEnumerable()
    8. Object.prototype.toLocaleString()
    9. Object.prototype.toSource()
    10. Object.prototype.toString()
    11. Object.prototype.unwatch()
    12. Object.prototype.valueOf()
    13. Object.prototype.watch()
    14. Object.setPrototypeOf()