map数据结构

作者: Clayten | 来源:发表于2018-04-03 16:20 被阅读0次

map：类似与对象，key-value 对的方式存储

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Document</title>
</head>
<body>
    <script type="text/javascript">
        let m = new Map();
        m.set("name","aaa");//设置
        m.set("age",20);
        console.log(m.get("name"));//读取
        for (let [k,v] of m){
            console.log(k+"=>"+v);
        }
        console.log(m.keys());
        console.log(m.values());
        console.log(m.entries());//整体输出
        // 对象转为map
        let u = {
            name : "Lucy",
            age : 20
        };
        let m1 = new Map();
        for ( let i in u){
            m1.set(i,u[i]);
        } 
        console.log(m1);
        //map=>对象
        let u1 ={};
        for ( let [k,v] of m1){
            u1[k] = v;
        }
        console.log(u1);
    </script>
</body>
</html>