ES6中的类

Posted 2022-11-18 rickyctbur

类的基本定义和生成实例：

    class Parent
        //定义构造函数 constructor 方法
        constructor(name=‘课程‘)
            this.name = name;
        
    
    //生成实例
    let parent1 = new Parent(‘慕课网‘);
    console.log(parent1)//Parent name: "慕课网"

 继承：

    class Parent
        //定义构造函数 constructor 方法
        constructor(name=‘旺财‘,sex = ‘男‘)
            this.name = name;
            this.sex = sex;
        
    
    console.log(new Parent())//Parent name: "旺财", sex: "男"
    class Child extends Parent
        constructor(name = ‘如花‘,sex=‘女‘,age = 15)
            super(name)//指定子类的默认参数不沿用父类的默认参数 若为空则所有默认参数都沿用父类的默认参数
            this.age = age;
        
    
    console.log(new Child())//Child name: "child", sex: "男", age: 15
    console.log(new Child(‘小强‘,undefined,18))//Child name: "小强", sex: "男", age: 18

 get和set的基本用法：

    class Parent
        //定义构造函数 constructor 方法
        constructor(name=‘旺财‘,sex = ‘男‘)
            this.name = name;
            this.sex = sex;
        
        get longName()
            return this.name
        
        set longName(value)
            this.name = value;
        
    
    let v = new Parent();
    console.log(v.longName)//旺财
    v.longName = ‘小强‘;
    console.log(v.longName)//小强

类的静态方法： 

    class Parent
        constructor(name=‘mukewang‘)
            this.name=name;
        
        static tell()  // 静态方法  关键字static
            console.log(‘tell‘);
        
    
    Parent.tell(); // tell      由类直接调用静态方法

静态属性： 

    class Parent
        constructor(name=‘mukewang‘)
            this.name=name;
        
        static tell()
            console.log(‘tell‘);
        
    
    Parent.type=‘test‘;//直接定义静态属性
    console.log(‘静态属性‘,Parent.type); //静态属性 test