类的继承.java

一些经典的java程序适合初学者.rar

//类的继承
class Father 
{  
      private int moneyDollar=300;
      int moneyHK=200;
      int add(int x,int y) 
      { 
          return x+y;
      }
}
class Son extends Father 
{   
      int  moneyRMB=120;
      public void changMoneyHK(int x)
      {
          moneyHK=x;  //继承的
      }
      int subs(int x,int y) //新增的  
      {   
          return x-y;    
      }
} 
class GrandSon extends Son
{
      public void changMoneyRMB(int x)
      {
          moneyRMB=x;//继承自上一级
      }
      int multi(int x,int y)//新增
      {
          return x*y;      
      }
}
public class Test
{  
    public static void main(String args[]) 
    { 
       int a=5,b=3; 
       Son son=new Son();
       GrandSon sunzi=new GrandSon();
       son.changMoneyHK(60);
       System.out.printf("儿子有港币,是继承的:%d,人民币,新增的的属性:%d\n",
                           son.moneyHK,son.moneyRMB);
       System.out.printf("儿子会减法,儿子新增的功能,%d-%d等于%d\n",
                           a,b,son.subs(a,b));
       System.out.printf("儿子还会加法,是继承的功能,%d+%d等于%d\n",
                           a,b,son.add(a,b)); 
       sunzi.changMoneyHK(20);
       sunzi.changMoneyRMB(10); 
       System.out.printf("孙子有港币,是继承的:%d,人民币:%d\n",
                           sunzi.moneyHK,sunzi.moneyRMB); 
       System.out.printf("孙子会乘法,孙子新增的功能,%d*%d等于%d\n",
                           a,b,sunzi.multi(a,b));   
       System.out.printf("孙子还会加法,是继承的功能,%d+%d等于%d\n",
                           a,b,sunzi.add(a,b)); 
       System.out.printf("孙子还会减法,是继承的功能,%d-%d等于%d\n",
                           a,b,sunzi.subs(a,b)); 
    }
}