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  • Uint8ClampedArray

    Uint8ClampedArray(8位无符号整型固定数组)类型化数组表示一个由值固定在0-255区间的8位无符号整型组成的数组;如果你指定一个在[0,255]区间外的值,它将被替换为0或255;如果你指定一个非整数,那么它将被设置为最接近它的整数。(数组)内容被初始化为0。一旦(数组)被创建,你可以使用对象的方法引用数组里的元素,或使用标准的数组索引语法(即使用方括号标记)。

    语法

    new Uint8ClampedArray(length);
    new Uint8ClampedArray(typedArray);
    new Uint8ClampedArray(object);
    new Uint8ClampedArray(buffer [, byteOffset [, length]]);
    

    关于构造函数语法和参数的更多信息,参见TypedArray

    属性

    Uint8ClampedArray.BYTES_PER_ELEMENT
    返回元素大小的一个数值。对Uint8ClampedArray而言是1。
    Uint8ClampedArray.length
    静态长度属性值为0。对于实际长度(元素的数量),见Uint8ClampedArray.prototype.length
    Uint8ClampedArray.name
    返回构造函数名的字符串值。对Uint8ClampedArray类型而言:"Uint8ClampedArray"。
    Uint8ClampedArray.prototype
    原型是TypedArray(类型化数组)对象。

    方法

    Uint8ClampedArray.from()
    从一个类数组或可枚举对象创建一个新的Uint8ClampedArray。参见Array.from()
    Uint8ClampedArray.of()
    通过一个可选数量参数来创建一个新的Uint8ClampedArray。参见Array.of()

    Uint8ClampedArray原型

    所有的Uint8ClampedArray对象继承自%TypedArray%.prototype

    属性

    Uint8ClampedArray.prototype.constructor
    返回创建一个实例原型的函数。这是Uint8ClampedArray默认的构造函数。
    Uint8ClampedArray.prototype.buffer只读
    返回由Uint8ClampedArray引用的ArrayBuffer。在创建时所固定下来,因此只能读取
    Uint8ClampedArray.prototype.byteLength只读
    返回从ArrayBuffer开始的Uint8ClampedArray的(字节的)长度。在创建时所固定下来,因此只能读取
    Uint8ClampedArray.prototype.byteOffset只读
    返回从ArrayBuffer开始的Uint8ClampedArray的(字节的)偏移。在创建时所固定下来,因此只能读取
    Uint8ClampedArray.prototype.length只读
    返回UintClamped8Array具有的元素数量。在创建时所固定下来,因此只能读取

    方法

    Uint8ClampedArray.prototype.copyWithin()
    复制数组内一段数组元素的序列。参见Array.prototype.copyWithin()
    Uint8ClampedArray.prototype.entries()
    返回一个新的包含数组中每个索引对应的键/值对的数组迭代器对象。参见Array.prototype.entries()
    Uint8ClampedArray.prototype.every()
    测试数组里的所有元素是否通过所提供的函数的测试。参见Array.prototype.every()
    Uint8ClampedArray.prototype.fill()
    用一个固定值填充一个数组内的从起始索引到结束索引的全部元素。参见Array.prototype.fill()
    Uint8ClampedArray.prototype.filter()
    由该数组中所有经所提供的筛选函数返回为 true 的元素创建一个新数组。参见Array.prototype.filter()
    Uint8ClampedArray.prototype.find()
    如果数组里的一个元素符合所提供的测试函数则返回找到的这个值,如果没有找到则返回undefined。参见Array.prototype.find()
    Uint8ClampedArray.prototype.findIndex()
    如果数组里的一个元素符合所提供的测试函数则返回找到的索引,如果没有找到则返回-1。参见Array.prototype.findIndex()
    Uint8ClampedArray.prototype.forEach()
    对数组内的每个元素调用一个函数。参见Array.prototype.forEach()
    Uint8ClampedArray.prototype.includes()
    确定一个类型化数组是否包含一个特定的元素,对应地返回truefalse。参见Array.prototype.includes()
    Uint8ClampedArray.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().
    Uint8ClampedArray.prototype.join()
    Joins all elements of an array into a string. See also Array.prototype.join().
    Uint8ClampedArray.prototype.keys()
    Returns a new Array Iterator that contains the keys for each index in the array. See also Array.prototype.keys().
    Uint8ClampedArray.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().
    Uint8ClampedArray.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().
    Uint8ClampedArray.prototype.move()未实现
    Former non-standard version of Uint8ClampedArray.prototype.copyWithin().
    Uint8ClampedArray.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().
    Uint8ClampedArray.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().
    Uint8ClampedArray.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().
    Uint8ClampedArray.prototype.set()
    Stores multiple values in the typed array, reading input values from a specified array.
    Uint8ClampedArray.prototype.slice()
    Extracts a section of an array and returns a new array. See also Array.prototype.slice().
    Uint8ClampedArray.prototype.some()
    Returns true if at least one element in this array satisfies the provided testing function. See also Array.prototype.some().
    Uint8ClampedArray.prototype.sort()
    Sorts the elements of an array in place and returns the array. See also Array.prototype.sort().
    Uint8ClampedArray.prototype.subarray()
    Returns a new Uint8ClampedArray from the given start and end element index.
    Uint8ClampedArray.prototype.values()
    Returns a new Array Iterator object that contains the values for each index in the array. See also Array.prototype.values().
    Uint8ClampedArray.prototype.toLocaleString()
    Returns a localized string representing the array and its elements. See also Array.prototype.toLocaleString().
    Uint8ClampedArray.prototype.toString()
    Returns a string representing the array and its elements. See also Array.prototype.toString().
    Uint8ClampedArray.prototype[@@iterator]()
    Returns a new Array Iterator object that contains the values for each index in the array.

    实例

    创建一个Uint8ClampedArray的不同方式:

    // From a length
    var uintc8 = new Uint8ClampedArray(2);
    uintc8[0] = 42;
    uintc8[1] = 1337;
    console.log(uintc8[0]); // 42
    console.log(uintc8[1]); // 255 (clamped)
    console.log(uintc8.length); // 2
    console.log(uintc8.BYTES_PER_ELEMENT); // 1
    
    // From an array
    var arr = new Uint8ClampedArray([21,31]);
    console.log(arr[1]); // 31
    
    // From another TypedArray
    var x = new Uint8ClampedArray([21, 31]);
    var y = new Uint8ClampedArray(x);
    console.log(y[0]); // 21
    
    // From an ArrayBuffer
    var buffer = new ArrayBuffer(8);
    var z = new Uint8ClampedArray(buffer, 1, 4);
    
    // From an iterable 
    var iterable = function*(){ yield* [1,2,3]; }(); 
    var uintc8 = new Uint8ClampedArray(iterable); 
    // Uint8ClampedArray[1, 2, 3]
    

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