// app8_8, “類變量”的使用
class CCircle   // 定義類CCircle
{
   private static int num=0;         // 設(shè)置num為“類變量”
   private static double pi=3.14;   // 設(shè)置pi為“類變量”
   private double radius;
 
   public CCircle(double r){ // CCircle構(gòu)造函數(shù)
      radius=r;
      num++;       // 當(dāng)CCircle()構(gòu)造函數(shù)被調(diào)用時(shí)，num便加1
   }      
   public void show(){  
      System.out.println("area="+pi*radius*radius);
   }
   public void count(){   // count() method，用來顯示目前對(duì)象建立的個(gè)數(shù)
      System.out.println(num+" object(s) created");      
   }   
}

public class app8_8
{
   public static void main(String args[])
   {
      CCircle cir1=new CCircle(1.0);
      cir1.count();       // 用cir1對(duì)象調(diào)用count() method
      CCircle cir2=new CCircle(2.0);
      cir1.count();       // 用cir1對(duì)象調(diào)用count() method
      cir2.count();       // 改用cir2對(duì)象調(diào)用count() method
   }
}