extend_super

package mypro01;

public class Animal {
   String name;
   int age=20;
   
   public void eat() {
       System.out.println("the animal is eating");
   }
   public Animal() {
       //所有的构造函数第一句是super（），如果不手动添加，编译器会自动添加
       super();
       System.out.println("create an animal");
   }
}


class Mammals extends Animal{
    String habbit;
    //重写方法override
    public void eat() {
        //调用父类的属性age
        System.out.println(super.age);
        //调用父类的eat方法
        super.eat();
        System.out.println("the mammals is eating");
    }
    public void sleep(){
        System.out.println("the mammals is sleeping");
    }
    
}

class Reptiles extends Animal{
    String life;
    public void play() {
        //调用父类的eat方法
        super.eat();
        System.out.println("the reptiles is playing");
    }
}