Int32Array

该Int32Array类型表示在平台顺序字节中一个双补码32位有符号的整型数组。如果需要控制字节顺序，请改用DataView。此内容的初始化为0。一旦创建，你可以使用对象的方法或者标准数组索引的语法(即使用括号表示法)。

语法

new Int32Array(length);
new Int32Array(typedArray);
new Int32Array(object);
new Int32Array(buffer [, byteOffset [, length]]);

更多关于构造函数语法和参数的详细信息，请参阅TypedArray。

属性

Int32Array.BYTES_PER_ELEMENTReturns a number value of the element size.4 in the case of an Int32Array.Int32Array.lengthStatic length property whose value is 3. For the actual length(number of elements), see Int32Array.prototype.length.Int32Array.nameReturns the string value of the constructor name. In the case of the Int32Array type:"Int32Array".Int32Array.prototypePrototype for the TypedArray objects.

方法

Int32Array.from()从类似数组或者可迭代对象中创建一个新的Int32Array。另见Array.from().Int32Array.of()创建一个新的具有可变数量参数的Int32Array。另见Array.of()。

Int32Array属性

所有的Int32Array对象都继承自{jsxref("TypedArray.prototype","%TypedArray%.prototype")}}。

属性

Int32Array.prototype.constructor返回创建实例原型的函数。默认情况下,它是Int32Array的构造函数。Int32Array.prototype.buffer只读返回在构造时被固定的Int32Array引用的ArrayBuffer，因此只读。Int32Array.prototype.byteLength只读返回从其ArrayBuffer开始的Int32Array长度的(以字节为单位)。在构造时被固定，因此只读。Int32Array.prototype.byteOffset只读返回从其ArrayBuffer开始的偏移量(以字节为单位)。在构造时被固定,因此只读。Int32Array.prototype.length只读返回Int32ArrayInt32Array包含的元素个数。在构造时被固定,因此只读。

方法

Int32Array.prototype.copyWithin()Copies a sequence of array elements within the array. See also Array.prototype.copyWithin().Int32Array.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().Int32Array.prototype.every()Tests whether all elements in the array pass the test provided by a function. See also Array.prototype.every().Int32Array.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().Int32Array.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().Int32Array.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().Int32Array.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().Int32Array.prototype.forEach()Calls a function for each element in the array. See also Array.prototype.forEach().Int32Array.prototype.includes()Determines whether a typed array includes a certain element, returning true or false as appropriate. See also Array.prototype.includes().Int32Array.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().Int32Array.prototype.join()Joins all elements of an array into a string. See also Array.prototype.join().Int32Array.prototype.keys()Returns a new Array Iterator that contains the keys for each index in the array. See also Array.prototype.keys().Int32Array.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().Int32Array.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().Int32Array.prototype.move()未实现Former non-standard version of Int32Array.prototype.copyWithin().Int32Array.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().Int32Array.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().Int32Array.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().Int32Array.prototype.set()在类型化数组中存储多个值，从指定数组中读取输入值。Int32Array.prototype.slice()提取数组中的一部分，并返回一个新的数组.更多请见Array.prototype.slice()。Int32Array.prototype.some()如果数组中至少有一个元素满足所提供的测试函数，则返回true。更多请见Array.prototype.some()。Int32Array.prototype.sort()Sorts the elements of an array in place and returns the array. See also Array.prototype.sort().Int32Array.prototype.subarray()Returns a new Int32Array from the given start and end element index.Int32Array.prototype.values()Returns a new Array Iterator object that contains the values for each index in the array. See also Array.prototype.values().Int32Array.prototype.toLocaleString()Returns a localized string representing the array and its elements. See also Array.prototype.toLocaleString().Int32Array.prototype.toString()Returns a string representing the array and its elements. See also Array.prototype.toString().Int32Array.prototype[@@iterator]()Returns a new Array Iterator object that contains the values for each index in the array.

例子

不同的方式创建一个Int32Array

// 从一个数字
var int32 = new Int32Array(2);
int32[0] = 42;
console.log(int32[0]); // 42
console.log(int32.length); // 2
console.log(int32.BYTES_PER_ELEMENT); // 4

// 从一个数组
var arr = new Int32Array([21,31]);
console.log(arr[1]); // 31

// 从一个其他TypedArray
var x = new Int32Array([21, 31]);
var y = new Int32Array(x);
console.log(y[0]); // 21

// 从一个ArrayBuffer
var buffer = new ArrayBuffer(16);
var z = new Int32Array(buffer, 0, 4);

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