【GET新技能】ES6的使用

ES6也成ES2015，是目前JavaScript的新标准；

1. new Set() 数组去重

let arr = [2,3,2,5,6,3];
let set = new Set(arr);
let newArr = Array.from(set);
alert(newArr);//[2,3,5,6]

2. forEach 数组循环

let arr = [2,3,2,5,6,3];
let list_el = '<ul>'
arr.forEach((value,index,self)=>{
    list_el += `<li>${value},${index}</li>`;
        //value  数组中的值
        //index  数组的索引
        //self    数组本身
});
list_el += '</ul>';
document.body.innerHTML = list_el;

输出结果

2,0
3,1
2,2
5,3
6,4
3,5

3. filter 数组过滤

let arr = [2,3,2,5,6,3];
let newArr = arr.filter((n)=>{
    return n != 2
});
alert(newArr);

输出结果：3,5,6,3

4. Object.assign() 对象合并方法 避免引用发生

let json1 = {a:1};
let json2 = {b:2};
let json3 = Object.assign({},json1,json2);
console.log(json3);//{a: 1, b: 2}
console.log(json1);//{a:1}
console.log(json2);//{b:2}

5. ....，es6扩展运算符
   

var arr = [1,2,3];
var arr2 = [...arr,4,5,6];
console.log(arr2); //[1,2,3,4,5,6]