Uint8Array

概述

Uint8Array 数组类型表示一个8位无符号整型数组，创建时内容被初始化为0。创建完后，可以以对象的方式或使用数组下标索引的方式引用数组中的元素。

语法格式

Uint8Array(length);//创建初始化为0的，包含length个元素的无符号整型数组
Uint8Array(typedArray);
Uint8Array(object);
Uint8Array(buffer [, byteOffset [, length]]);

For more information about the constructor syntax and the parameters, see 构造语法和参数的更多信息请参见TypedArray.

属性

Uint8Array.BYTES_PER_ELEMENT

Returns a number value of the element size. 1 in the case of an Uint8Array.返回数组中元素字节数，Uint8Array中返回1字节。

Uint8Array.length

Length property whose value is 3长度属性，它的值是3.

Uint8Array.name

Returns the string value of the constructor name. In the case of the Uint8Array type: "Uint8Array".返回构造名的字符串，对Uint8Array而言返回类型“Uint8Array”

Uint8Array.prototype

Prototype for the TypedArray objects 对TypedArray对象的原型声明.
    。

方法

Uint8Array.from()

Creates a new Uint8Array from an array-like or iterable object. See also 从一个数组或可迭代的对象创建一个新的Uint8Array数组，可参见Array.from().

Uint8Array.of()

Creates a new Uint8Array with a variable number of arguments. See also 通过一个可变数目的参数创建一个新的Uint8Array数组，可参见Array.of().

Uint8Array 原型声明

All Uint8Array objects inherit from所有的Uint8Array对象继承自 %TypedArray%.prototype.

Properties

Uint8Array.prototype.constructor

Returns the function that created an instance's prototype. This is the Uint8Array constructor by default.

Uint8Array.prototype.buffer 只读

Returns the ArrayBuffer referenced by the Uint8Array Fixed at construction time and thus read only.

Uint8Array.prototype.byteLength 只读

Returns the length (in bytes) of the Uint8Array from the start of its ArrayBuffer. Fixed at construction time and thus read only.

Uint8Array.prototype.byteOffset 只读

Returns the offset (in bytes) of the Uint8Array from the start of its ArrayBuffer. Fixed at construction time and thus read only.

Uint8Array.prototype.length 只读

Returns the number of elements hold in the Uint8Array. Fixed at construction time and thus read only.

Methods

Uint8Array.prototype.copyWithin()

Copies a sequence of array elements within the array. See also Array.prototype.copyWithin().

Uint8Array.prototype.entries()

Returns a new Array Iterator object that contains the key/value pairs for each index in the array. See also Array.prototype.entries().

Uint8Array.prototype.every()

Tests whether all elements in the array pass the test provided by a function. See also Array.prototype.every().

Uint8Array.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().

Uint8Array.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().

Uint8Array.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 also Array.prototype.find().

Uint8Array.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().

Uint8Array.prototype.forEach()

Calls a function for each element in the array. See also Array.prototype.forEach().

Uint8Array.prototype.includes()

Determines whether a typed array includes a certain element, returning true or false as appropriate. See also Array.prototype.includes().

Uint8Array.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().

Uint8Array.prototype.join()

Joins all elements of an array into a string. See also Array.prototype.join().

Uint8Array.prototype.keys()

Returns a new Array Iterator that contains the keys for each index in the array. See also Array.prototype.keys().

Uint8Array.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().

Uint8Array.prototype.map()

Creates a new array with the results of calling a provided function on every element in this array. See also Array.prototype.map().

Uint8Array.prototype.move() 未实现

Former non-standard version of Uint8Array.prototype.copyWithin().

Uint8Array.prototype.reduce()

Apply a function against an accumulator and each value of the array (from left-to-right) as to reduce it to a single value. See also Array.prototype.reduce().

Uint8Array.prototype.reduceRight()

Apply a function against an accumulator and each value of the array (from right-to-left) as to reduce it to a single value. See also Array.prototype.reduceRight().

Uint8Array.prototype.reverse()

Reverses the order of the elements of an array — the first becomes the last, and the last becomes the first. See also Array.prototype.reverse().

Uint8Array.prototype.set()

Stores multiple values in the typed array, reading input values from a specified array.

Uint8Array.prototype.slice()

Extracts a section of an array and returns a new array. See also Array.prototype.slice().

Uint8Array.prototype.some()

Returns true if at least one element in this array satisfies the provided testing function. See also Array.prototype.some().

Uint8Array.prototype.sort()

Sorts the elements of an array in place and returns the array. See also Array.prototype.sort().

Uint8Array.prototype.subarray()

Returns a new Uint8Array from the given start and end element index.

Uint8Array.prototype.values()

Returns a new Array Iterator object that contains the values for each index in the array. See also Array.prototype.values().

Uint8Array.prototype.toLocaleString()

Returns a localized string representing the array and its elements. See also Array.prototype.toLocaleString().

Uint8Array.prototype.toString()

Returns a string representing the array and its elements. See also Array.prototype.toString().

Uint8Array.prototype[@@iterator]()

Returns a new Array Iterator object that contains the values for each index in the array.

Examples

// From a length
var uint8 = new Uint8Array(2);
uint8[0] = 42;
console.log(uint8[0]); // 42
console.log(uint8.length); // 2
console.log(uint8.BYTES_PER_ELEMENT); // 1

// From an array
var arr = new Uint8Array([21,31]);
console.log(arr[1]); // 31

// From another TypedArray
var x = new Uint8Array([21, 31]);
var y = new Uint8Array(x);
console.log(y[0]); // 21

// From an ArrayBuffer
var buffer = new ArrayBuffer(8);
var z = new Uint8Array(buffer, 1, 4);

Specifications

Browser compatibility

See also

• JavaScript typed arrays
• ArrayBuffer
• DataView