给前端介绍对象啦！(TypeScript 版)（三）

class Cat extends Animal {       public eat() {//多态 扩展原方法               super.eat();               console.log("I like eating fish");       }       public say() {               console.log("Miao~");       }       public catchMouse() {               //...       }}

let myCat: Animal = new Cat("XiaoHua", 3);       myCat.eat();//I am eating someting     I like eating fish       myCat.say();//Miao~

interface Flyable {       fly();}interface catchBug {       catchBug();}class Bird extends Animal implements Flyable,catchBug {       public say() {               console.log("Ji~Ji~Zha~Zha~");       }       public fly() {               console.log("I am flying with flapping my wings");       }       public catchBug() {               //...       }}class Plane implements Flyable {       fly() {               console.log("I am flying with my engines");       }       takePeople() {               //...       }}

let flyable1: Flyable = new Bird("Polly", 1);       flyable1.fly(); //I am flying with flapping my wings       // flyable1.eat();//编译报错: 不存在eat()
       let flyable2: Flyable = new Plane();       flyable2.fly();//I am flying with my engines

class People extends Animal{       constructor(public name: string, public age: number,public pet: Animal) {               super(name,age);       };       public say(){               console.log(`My name is ${this.name}, I am ${this.age} years old, my pet's name is ${this.pet.name}`);       }}

let myBrother: People = new People("XiaoMing", 18, new Dog("GouDan", 2));      myBrother.say();//My name is XiaoMing, I am 12 years old, my pet's name is GouDan      console.log('totalNum='+Animal.totalNum);//totalNum=5 //Dog/Cat/Bird/Dog/People/