13 class

// es5造类
/* function Person(name,age) {
    this.name = name;
    this.age = age;
}
Person.prototype.sayName = function() {
    return this.name;
}
let p1 = new Person('小马哥',28);
console.log(p1);
    */
class Person {
    // 实例化的时候会立即被调用
    constructor(name, age) {
        this.name = name;
        this.age = age;
    }
    sayName() {
        return this.name
    }
}
// 通过Object.assign()方法一次性向类中添加多个方法
Object.assign(Person.prototype, {
    sayName2() {
        return this.name
    },
    sayAge() {
        return this.age
    }
})
let p1 = new Person('小马哥', 28);
console.log(p1);

类的继承

// 使用关键字 extends
class Animal{// es5造类
/* function Person(name,age) {
    this.name = name;
    this.age = age;
}
Person.prototype.sayName = function() {
    return this.name;
}
let p1 = new Person('小马哥',28);
console.log(p1);
    */
class Person {
    // 实例化的时候会立即被调用
    constructor(name, age) {
        this.name = name;
        this.age = age;
    }
    sayName() {
        return this.name
    }
}
// 通过Object.assign()方法一次性向类中添加多个方法
Object.assign(Person.prototype, {
    sayName2() {
        return this.name
    },
    sayAge() {
        return this.age
    }
})
let p1 = new Person('小马哥', 28);
console.log(p1);
    constructor(name,age) {
        this.name = name;
        this.age = age;
    }
    sayName(){
        return this.name;
    }
    sayAge(){
        return this.age;
    }
}
class Dog extends Animal{
    constructor(name,age,color) {
        super(name,age);
        // Animal.call(this,name,age);
        this.color = color;
    }
    // 子类自己的方法
    sayColor(){
        return `${this.name}是${this.age}岁了,它的颜色是${this.color}`
    }
    // 重写父类的方法
    sayName(){
        return this.name + super.sayAge() + this.color;
    }
}
let d1 = new Dog('小黄',28,'red');
console.log(d1.sayColor());
console.log(d1.sayName());