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

时间:2021-08-04 18:28:14

//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
 
//es5使用apply比较完美继承Array的方法 start

function MyArray(){
  Array.apply(this,arguments);
}
MyArray.prototype = new Array()
MyArray.prototype.constructor = MyArray
const colors = new MyArray();

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

colors.length = 0;
console.log(colors[0]);
//es5使用apply比较完美继承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

  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