CoreJava/exp4/AnimalTool.java

package exp4;

abstract class Animal{
    String name;
    int age;

    public Animal(){};
    public Animal(String name, int age){
        this.name = name;
        this.age = age;
    }

    abstract void eat();
    abstract void show();
}

class Cat extends Animal{
    public Cat(){};
    public Cat(String name, int age){
        super(name, age);
    }

    void eat(){
        System.out.println("猫吃鱼");
    }

    void show(){
        System.out.println(this.name+","+this.age);
    }
}

class Dog extends Animal{
    public Dog(){};
    public Dog(String name, int age){
        super(name, age);
    }

    void eat(){
        System.out.println("狗吃肉");
    }

    void show(){
        System.out.println(this.name+","+this.age);
    }
}


public class AnimalTool {
    public static void main(String[] args){
        Animal a = new Cat();
        Animal b = new Dog("旺财", 3);

        a.name = "Tom";
        a.age = 999;

        a.show();
        b.show();

        a.eat();
        b.eat();
    }
}