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Int8Array
类型数组为8位二进制补码有符号整数的数组. 初始化内容为0. 你可以使用构造对象来初始化一个Int8Array对象, 也可以使用标准的数组语法 (大括号语法初始化).
语法
new Int8Array(length); new Int8Array(typedArray); new Int8Array(object); new Int8Array(buffer [, byteOffset [, length]]);
获得构造器语法与参数的更多信息,请访问 TypedArray.
属性
Int8Array.BYTES_PER_ELEMENT
- 返回数组中每个元素的大小. 在
Int8Array中这个值为1
. - Int8Array.length
- 此属性为固定值属性,值为3.查看
Int8Array.prototype.length
获得获取数组内元素个数方法。 Int8Array.name
- 返回构造器方法名称.在Int8Array类型中此值为 "Int8Array"。
Int8Array.prototype
- TypedArray 对象的构造原型。
方法
Int8Array.from()
- 从类数组对象或迭代器生成int8Array数组对象. 参照
Array.from()
. Int8Array.of()
- 以多个参数构造Int8Array对象, 参照
Array.of()
.
Int8Array
原型方法
Int8Array所有方法继承自
%TypedArray%.prototype
.
属性
Int8Array.prototype.constructor
- 这个方法会返回对象的构造原型. 默认为
Int8Array构造函数
. Int8Array.prototype.buffer
只读- Returns the
ArrayBuffer
referenced by theInt8Array
Fixed at construction time and thus read only. Int8Array.prototype.byteLength
只读- Returns the length (in bytes) of the
Int8Array
from the start of itsArrayBuffer
. Fixed at construction time and thus read only. Int8Array.prototype.byteOffset
只读- Returns the offset (in bytes) of the
Int8Array
from the start of itsArrayBuffer
. Fixed at construction time and thus read only. Int8Array.prototype.length
只读- Returns the number of elements hold in the
Int8Array
. Fixed at construction time and thus read only.
方法
Int8Array.prototype.copyWithin()
- Copies a sequence of array elements within the array. See also
Array.prototype.copyWithin()
. Int8Array.prototype.entries()
- Returns a new
Array Iterator
object that contains the key/value pairs for each index in the array. See alsoArray.prototype.entries()
. Int8Array.prototype.every()
- Tests whether all elements in the array pass the test provided by a function. See also
Array.prototype.every()
. Int8Array.prototype.fill()
- Fills all the elements of an array from a start index to an end index with a static value. See also
Array.prototype.fill()
. Int8Array.prototype.filter()
- Creates a new array with all of the elements of this array for which the provided filtering function returns true. See also
Array.prototype.filter()
. Int8Array.prototype.find()
- Returns the found value in the array, if an element in the array satisfies the provided testing function or
undefined
if not found. See alsoArray.prototype.find()
. Int8Array.prototype.findIndex()
- Returns the found index in the array, if an element in the array satisfies the provided testing function or -1 if not found. See also
Array.prototype.findIndex()
. Int8Array.prototype.forEach()
- Calls a function for each element in the array. See also
Array.prototype.forEach()
. Int8Array.prototype.includes()
- Determines whether a typed array includes a certain element, returning
true
orfalse
as appropriate. See alsoArray.prototype.includes()
. Int8Array.prototype.indexOf()
- Returns the first (least) index of an element within the array equal to the specified value, or -1 if none is found. See also
Array.prototype.indexOf()
. Int8Array.prototype.join()
- Joins all elements of an array into a string. See also
Array.prototype.join()
. Int8Array.prototype.keys()
- Returns a new
Array Iterator
that contains the keys for each index in the array. See alsoArray.prototype.keys()
. Int8Array.prototype.lastIndexOf()
- Returns the last (greatest) index of an element within the array equal to the specified value, or -1 if none is found. See also
Array.prototype.lastIndexOf()
. Int8Array.prototype.map()
- 返回一个由回调函数的返回值组成的新数组。. See also
Array.prototype.map()
. Int8Array.prototype.move()
未实现Int8Array.prototype.copyWithin()
早期的不标准定义。Int8Array.prototype.reduce()
- 从左到右为每个数组元素执行一次回调函数,并把上次回调函数的返回值放在一个暂存器中传给下次回调函数,并返回最后一次回调函数的返回值。参照
Array.prototype.reduce()
. Int8Array.prototype.reduceRight()
- 从右到左为每个数组元素执行一次回调函数,并把上次回调函数的返回值放在一个暂存器中传给下次回调函数,并返回最后一次回调函数的返回值。参照
Array.prototype.reduceRight()
. Int8Array.prototype.reverse()
- 颠倒数组中元素的排列顺序,即原先的第一个变为最后一个,原先的最后一个变为第一个。参照
Array.prototype.reverse()
. Int8Array.prototype.set()
- Stores multiple values in the typed array, reading input values from a specified array.
Int8Array.prototype.slice()
- 抽取当前数组中的一段元素组合成一个新数组。参照
Array.prototype.slice()
. Int8Array.prototype.some()
- 如果数组中至少有一个元素满足测试函数,则返回 true,否则返回 false。参照
Array.prototype.some()
. Int8Array.prototype.sort()
- 对数组元素进行排序,并返回当前数组. 参照
Array.prototype.sort()
. Int8Array.prototype.subarray()
- 返回一个以给定的初始结束位置裁剪的Int8Array数组.
Int8Array.prototype.values()
- 返回一个数组迭代器对象,该迭代器会包含所有数组元素的值。. 参照
Array.prototype.values()
. Int8Array.prototype.toLocaleString()
- 返回一个由所有数组元素组合而成的本地化后的字符串. See also
Array.prototype.toLocaleString()
. Int8Array.prototype.toString()
- 返回一个由所有数组元素组合而成的字符串.参照
Array.prototype.toString()
. Int8Array.prototype[@@iterator]()
- 此方法返回一个带有数组内所有元素的迭代器对象,同Int8Array.prototype.values 。
示例
// 以长度参数构造对象 var int8 = new Int8Array(2); int8[0] = 42; console.log(int8[0]); // 42 console.log(int8.length); // 2 console.log(int8.BYTES_PER_ELEMENT); // 1 // 以数组构造对象 var arr = new Int8Array([21,31]); console.log(arr[1]); // 31 // 从另一数组构造对象 var x = new Int8Array([21, 31]); var y = new Int8Array(x); console.log(y[0]); // 21 // 从ArrayBuffer构造对象 var buffer = new ArrayBuffer(8); var z = new Int8Array(buffer, 1, 4);
规范
规范 | 状态 | 评论 |
---|---|---|
Typed Array Specification | Obsolete | 已被 ECMAScript 6取代。 |
ECMAScript 2015 (6th Edition, ECMA-262) TypedArray constructors |
Standard | ECMA 标准中构造对象时 new 关键字为必需。 |
ECMAScript 2017 Draft (ECMA-262) TypedArray constructors |
Draft |
浏览器支持
功能 | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|
Basic support | 7.0 | 4.0 (2) | 10 | 11.6 | 5.1 |
new is required |
? | 44 (44) | ? | ? | ? |
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 |
new is required |
? | ? | 44.0 (44) | ? | ? | ? |
兼容性说明
自 ECMAScript 2015 (ES6)施行, Int8Array
需要使用new
构造. 从当前版本开始,不加new而便调用Int8Array
构造器方法, 将报出 TypeError
错误.
var dv = Int8Array([1, 2, 3]); // TypeError: calling a builtin Int8Array constructor // without new is forbidden
var dv = new Int8Array([1, 2, 3]);