class创建类和数组和类的解构

一、用class创建一个类, 并实现自有,共享,静态成员的声明与输出

...
    <script>
    ...
        class demo {
            //公共成员
            username = '小明';
            //构造方法
            constructor(name, email){
                //自有属性
                this.name = name;
                this.email = email;
            }
            //共享成员：原型成员
            getInfo(){
                return `${this.name}:(${this.email})`
            }
            //静态成员
            static status = 'enable';
        }
        const obj = new demo('晓东','xiaodong@php.cn');
        console.log(obj.getInfo());
        console.log(obj.status);
        console.log(demo.status);
    ...
    </script>
...

二、实例演示数组与对象解构方法

数组解构

...
    <script>
    ...
        const user = ['小明', 'xiaoming@php.cn'];
        let username = user[0];
        let useremail = user[1];
        console.log(username, useremail);
        console.log('------数组解构------'); 
        let [username1, useremail1]=['晓东', 'xiaodong@php.cn'];
        console.log(username1, useremail1);
        console.log('------更新值------');
        [username1, useremail1]=['李晓东', 'xiaodong@php.cn'];
        console.log(username1, useremail1);
        console.log('------参数不足，给默认值。------');
        [username1, useremail1, age = 30]=['李晓东', 'xiaodong@php.cn'];
        console.log(username1, useremail1, age);
        console.log('------参数过多，使用“...”接收------');
        [a, b, c, ...arr] = [1, 2, 3, 4, 5, 6, 7, 8, 9]
        console.log(a, b, c);
        console.log(arr);
        console.log('------解构用在数值交换------');
        let x = 10;
        let y = 20;
        console.log(x, y);
        [y, x] = [x, y];
        console.log(x, y);
    ...
    </script>
...

对象解构

...
    <script>
    ...
        let {id, lesson, score} = {id:1, lesson:'js', score:88};
        console.log(id, lesson, score);
        console.log('------更新值------');
        ({id, lesson, score} = {id:2, lesson:'php', score:98})
        console.log(id, lesson, score);
        console.log('------命名冲突，起别名。------');
        let {id:itemID, num, price} = {id:3, num:10, price:8.8};
        console.log(itemID, num, price);
        console.log('------类解构应用------');
        let user = {id:145, name:'牛牛', email:'niu@php.cn'};
        function getUser({id, name, email}){
            console.log(id, name, email);
        }
        getUser(user);
    ...
    </script>
...