catsanddogs.java

java编程思想的部分实现

//c09:CatsAndDogs.java
import java.util.*;
class Cat
{
	private int catNumber;
	Cat(int i){catNumber=i;}
	void print()
	{
		System.out.println("Cat#"+catNumber);
	}
}

class Dog
{
	private int dogNumber;
	Dog(int i){dogNumber=i;}
	void print()
	{
		System.out.println("Dog#"+dogNumber);
	}
}


public class CatsAndDogs
{
	public static void main(String[]args)
	{
		ArrayList cats=new ArrayList();
		for(int i=0;i<7;i++)
		{
			cats.add(new Cat(i));
		}
	  cats.add(new Dog(7));
	  for(int i=0;i<cats.size();i++)
	  {
	  	((Cat)cats.get(i)).print();
	  }
	}
}