~~~ // Es6類 class Persion2{ //構造函數 必須constructor constructor(name,age){ this.name=name; this.age=age; } //方法：必須方法名+()+{} say4(){ console.log(this.name+this.age) } } var Persion4=new Persion2("dash4",21); console.log(Persion4); Persion4.say4(); ~~~ ``` function person(){ } //向函數對象追加屬性，即向Function追加屬性 person.name="tom"; person.say=function(){console.log("hello world!")} //向原型對象追加屬性（實例對象可訪問）相當于向父類追加屬性 person.prototype.sex="男"; var p=new person(); console.log(person.name);//tom console.log(p.name);//undefined console.log(p.sex);//男 //函數對象的屬性屬于類，不屬于實例對象 //在Es6中 函數對象用static聲明 class person{ constructor(sex) { this.sex="男"; } static name= "tom"; static say(){ console.log("hello world!"); } } let p=new person(); console.log(person.name)//tom console.log(p.name);//undefined console.log(p.sex);//男 ``` ## **繼承與方法重寫** ``` // 老版本 function User(name, pass) { this.name = name this.pass = pass } User.prototype.showName = function () { console.log(this.name) } User.prototype.showPass = function () { console.log(this.pass) } var u1 = new User('able', '1233') u1.showName() u1.showPass() // 老版本繼承 function VipUser(name, pass, level) { //call()它可以用來調用所有者對象作為參數的方法 //通過call()，您能夠使用屬于另一個對象的方法 User.call(this, name, pass) this.level = level } VipUser.prototype = new User() VipUser.prototype.constructor = VipUser VipUser.prototype.showLevel = function () { console.log(this.level) } var v1 = new VipUser('blue', '1234', 3) v1.showName() v1.showLevel() ``` ES6 ``` class User { constructor(name, pass) { this.name = name this.pass = pass } showName() { console.log(this.name) } showPass() { console.log(this.pass) } } var u1 = new User('able2', '111') u1.showName() u1.showPass() // 新版本繼承 class VipUser extends User { constructor(name, pass, level) { super(name, pass) this.level = level } showLevel(){ console.log(this.level) } //重寫父類方法 showName() { console.log("重寫啦！") } } v1 = new VipUser('blue', '123', 3) v1.showLevel() v1.showName() ``` ## **getter與setter** get：當獲取屬性是觸發 set當設置屬性樹觸發 ``` class person{ get age(){ console.log("獲取年齡"); } set age(age){ console.log("設置年齡"); } } let p=new person(20); p.age=20 p.age ```