let args = [].slice.call(arguments) let imgs= [].slice.call(document.querySelectorAll('img'))//NodeList ES6伪数组转换为数组 let args = Array.from(arguments) let imgs = Array.from(document.querySelectorAll('img')) Array
Function.prototype.myBind = function (thisArg, ...args) {` var self = this// new优先级var fbound = function () {self.apply(this instanceof self ? this : thisArg, args.concat(Array.prototype.slice.call(arguments)))}// 继承原型上的属性和方法fbound.prototype = Object.create(self...
varargs =1; } 而let修复了这种不严谨的设计: functionfuncA(){ leta =1; leta =2;// Uncaught SyntaxError: Identifier 'a' has already been declared } functionfuncB(args){ letargs =1;// Uncaught SyntaxError: Identifier 'args' has already been declared } 现在我们项目中已经完全放弃了var,而使...
assign || function(){ if(arguments.length == 0) throw new TypeError('Cannot convert undefined or null to object'); let target = arguments[0], args = Array.prototype.slice.call(arguments, 1), key args.forEach(function(item){ for(key in item){ item.hasOwnProperty(key) && ( target[...
Array.prototype.flatMap() TheflatMap()method returns a new array formed by applying a given callback function to each element of the array, and then flattening the result by one level. It is identical to amap()followed by aflat()of depth 1 (arr.map(...args).flat()), but slightly ...
Array.from() 再ES6中可以直接用Array.from() 将伪数组转换为数组 Array.from() 也可以用于初始化数组 function test(num1,num2,num3,num4,num5,num6){ let args = Array.from(arguments) console.log(args) } test(1,2,3,4,5,6); //args 显示为数组类型 语法:Array.from(arrayLike,mapFn,thisA...
Plus, rest arguments are a real Array, and not merely Array-like like arguments. // bad function concatenateAll() { const args = Array.prototype.slice.call(arguments); return args.join(''); } // good function concatenateAll(...args) { return args.join(''); }...
let slice = Array . prototype . slice , // 将slice缓存起来 args = slice . call ( arguments , 1 ); // 这里将arguments转成数组并保存 return function { // 将新旧的参数拼接起来 let newArgs = args . concat ( slice . call ( arguments )); ...
1.属性Set.prototype.constructor:构造函数,默认就是Set函数。Set.prototype.size:返回Set实例的成员总数。2.Set实例的方法分为两大类:操作方法(用于操作数据)和遍历方法(用于遍历成员)。 下面先介绍四个操作方法:add(value):添加某个值,返回Set结构本身。delete(value):删除某个值,返回一个布尔值,表示删除是否成功...
functionfuncB(args){ letargs =1;// Uncaught SyntaxError: Identifier 'args' has already been declared } 现在我们项目中已经完全放弃了var,而使用let来定义变量,使用const来定义常量。在ESlint开启了如下规则: "no-var":0; 2. 解构赋值 ES6中还引入了解构赋值的概念,解构赋值遵循“模式匹配”,即只要等号两...