如何在main方法里调用子类中独有方法？

Question

package com.imooc;public class Dog extends Animal {   public void eat(){    System.out.println("狗是吃肉的");   }   public void watchDoor(){    System.out.println("狗具有看门的能力");   }}package com.imooc;public class Initail { /**  * @param args  */ public static void main(String[] args) {  // TODO Auto-generated method stub        Animal obj1 = new Animal();        Animal obj2 = new Dog();//父类指向子类        Animal obj3 = new Cat();        obj1.eat();        obj2.eat();        obj3.eat();        ——————？ }}

Answer 1

强转为子类类型,然后调用子类独有方法 Animal obj2 = new Dog(); (Dog)obj2.watchDoor();