清华大学：JAVA教学课件：5-8

程序5-9
class Count{
int serialNumber;
static int counter =0; //类变量
public Count(){
counter++;
serialNumber = counter;
}
}
public class UseStatic{
public static void main(String args[]){
System.out.println("Count.counter is "+Count.counter);
Count Tom = new Count();
Count John = new Count();
System.out.println("Tom's serialNumber is "+Tom.serialNumber);
System.out.println("John's serialNumber is "+John.serialNumber);
System.out.println("Now Count.counter is " + Count.counter);
}
}