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

Posted 2021-03-20 问问大将军

//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