es6 class的基础语法,es6 class继承/ es5 call继承描述/使用es6完美继承Array的方法 sort倒序排序console.table()表格生成

//基础语法
function
People(name,email){ name, email } class User{ constructor(name,email){ this.name = name; this.email = email; } getinfo(){ console.log(this.name); } static description(){ console.log('I am description --static'); } set urls(values){ console.log(values); this.urlsvalue = values; } get urls(){ return `hello urls ${this.urlsvalue}`; } }



//class 实现继承(附带es5继承方法)
class Animal {
    constructor(name){
        this.name = name;
        this.belly = [];
    }
    eat(food){
        this.belly.push(food);
    }
    speak(){
        console.log('I am lucky')
    }
}
class Dog extends Animal{
    constructor(name,age){
        super(name);
        this.age = age;
    }
    bark(){
        console.log('bark bark!');
    }
    speak(){
        console.log('bark bark I am lucky')
    }
}
const lucky = new Dog('lucky',2)


console.log(lucky.speak()) //bark bark I am lucky   同个方法会覆盖父类方法

// es5的继承方式比较复杂
// start
// function Dog(name,age){
//     Animal.call(this,name,age);//在子类的构造函数当中,首先会调用基类的构造函数,es6中直接super()即可。
//     this.name = name;
//     this.age = age;
// }
// Dog.prototype = new Animal(); //Dog原型对象被指向Animal的实例,constructor会被改变,所以需要下面声明下construcor 指向Dog
// Dog.prototype.constructor = Dog;
// end
 

//es6完美继承Array的方法 start
class MyArray extends Array{
  constructor(){
    super();
  }
}

const colors = new MyArray();

colors[0] = 'red';
console.log(colors.length);

colors.length = 0;
console.log(colors[0]);
//完美继承Array的方法 end



class movieCollection extends Array{
	constructor(name,...values){
		super(...values);
		this.name = name
	}
	topRated(limit = 10){
		return this.sort((a,b) => (a.scores > b.scores) ? -1:1).slice(0,limit);  //倒序排序
	}
}
const movies = new movieCollection('Leo',
	{name:'功夫熊猫',scores:8.7},
	{name:'Gongfu',scores:9.7},
	{name:'trjei',scores:10},
)
movies.push({name:'ddddd',scores:4})

console.table(movies.topRated()) //会生成一个倒序表格,牛逼了

  

posted @ 2019-12-26 22:35  问问大将军  阅读(349)  评论(0编辑  收藏  举报