transtype.java

Java面向对象编程(随书配套源代码) 阐述了面向对象编程的思想

package chapter7;

import java.util.Random;

public class TransType
{
	public static void main(String args[])
	{
		Wolf wolf = new Wolf();
		Sheep sheep = new Sheep();
		Duck duck = new Duck();
		Goal goal = new Goal();
		Animal animal[] = {wolf,sheep,duck,goal};
		duck = null;
		duck = (Duck) animal[2];
		duck.layEgg( ); 
		
		if(animal[2] instanceof Wolf)
		{
		   wolf = (Wolf) animal[2];
		   wolf.eat("羊");
		}
		Random random = new Random();
		Animal aniObj = animal[random.nextInt(4)];
		if(aniObj instanceof Wolf)
		{
			aniObj.eat("羊");
		}
		else if(aniObj instanceof Sheep)
		{
			aniObj.eat("草");
		}
		else if(aniObj instanceof Duck)
		{
			duck = (Duck) aniObj;
			duck.layEgg();
		}
		else
		{
			System.out.println("我是一个怪物！");
		}
		
		StaticNestedOuterClass outer = new StaticNestedOuterClass();
		//StaticNestedOuterClass.innerClass inner = outer.new innerClass() ;
	}
	
}