2019网站seo广西seo优化

ES6提供了 Map数据结构。它类似于对象，也是键值对的集合。但是“键”的范围不限于字符串，各种类型的值（包括对象）都可以当作键。

创建方法

    let m = new Map()console.log(m)

Map的方法

1.set( )
添加元素
接收两个参数，第一个键名，第二个键值

    let m = new Map()m.set("name","zs")m.set("age",18)let key = {hobby : "爱好"}m.set(key,["唱","跳","rap","篮球"])console.log(m)

2.size在这里插入代码片
获取元素个数

    let m = new Map()m.set("name","zs")console.log(m.size) //1

3.delete( )
删除元素

    let m = new Map()m.set("name","zs")m.delete("name")console.log(m)

4.get( )
获取元素

    let m = new Map()m.set("name","zs")console.log(m.get("name")) //zs

5.clear( )
清空

    let m = new Map()m.set("name","zs")m.clear()console.log(m)

6.entries( )
返回 Map 对象中键/值对的数组

    let m = new Map()m.set("name","zs")m.set("age",18)let key = {hobby : "爱好"}m.set(key,["唱","跳","rap","篮球"])console.log(m.entries())

7.keys( )
返回 Map 对象中键的数组

    let m = new Map()m.set("name","zs")m.set("age",18)let key = {hobby : "爱好"}m.set(key,["唱","跳","rap","篮球"])console.log(m.keys())

8.values( )
返回 Map 对象中值的数组

    let m = new Map()m.set("name","zs")m.set("age",18)let key = {hobby : "爱好"}m.set(key,["唱","跳","rap","篮球"])console.log(m.values())

9.遍历for…of

    let m = new Map()m.set("name","zs")m.set("age",18)let key = {hobby : "爱好"}m.set(key,["唱","跳","rap","篮球"])for(let v of m) {console.log(v)}

10.forEach
返回键和值回调

    let m = new Map()m.set("name","zs")m.set("age",18)let key = {hobby : "爱好"}m.set(key,["唱","跳","rap","篮球"])m.forEach(item=>{console.log(item)})

感谢大家的阅读，如有不对的地方，可以向我提出，感谢大家！