关于es6:ES6-Arrayform

Array.form

• 作用：将数组、类数组、带有索引和length属性的对象、Set对象、Map对象、字符串转换为实在数组
• 参数：第一个参数为要转换的数据（必选）、第二个参数为function,相似map办法（可选）。
• 返回值：返回解决后的新数组

示例：
let obj = {

    "0":"a",    "1":"b",    "2":"c",    "length":3}console.log(Array.from(obj));//["a", "b", "c"]let arr = [0,1,2];let set = new Set(arr);console.log(Array.from(set));//[0, 1, 2]let map = new Map();map.set("name","Archer");map.set("age","18");console.log(Array.from(map));//[["name", "Archer"],["age", "18"]]let str = "Archer";console.log(Array.from(str));//["A", "r", "c", "h", "e", "r"]let Arr = [0,1,2,3];var Arr2 = Array.from(Arr);console.log(Arr2);//[0,1,2,3]console.log(Arr == Arr2);//falselet Arr3 = [0,1,2];let Arr4 = Array.from(Arr3,(item,index) =>{    return item + 1;})console.log(Arr4);//[1, 2, 3]