ES6 Class類（簡單理解封裝和繼承）

        class People{
            constructor({name}){
                this.name = name;
            }
            say(){
                return "hello";
            }
        }

        const people = new People({name:"tom"});
        console.log(people);   // People {name:"tom"}
        console.log(people.say())  //hello

        //繼承
        class Jack extends People{   //Jack 繼承於 People
            constructor(options){
                super(options)   //調用super方法之前 要給類繼承父級
                this.age = options.age;
            }
        }

        const jack = new Jack({age:18,name:"jack"})
        console.log(jack)   //Jack {age:18,name:"jack"}
        console.log(jack.say())  //hello