1 public class Cat {
 2     private static int sid = 0;
 3     private String name; 
 4     int id;
 5     Cat(String name) {
 6         this.name = name;  
 7         id = sid++;
 8     }
 9     public void info(){
10         System.out.println
11                ("My name is "+name+" No."+id);
12     }
13     public static void main(String arg[]){
14 
15         Cat.sid = 100;
16         Cat mimi = new Cat("mimi");17         Cat pipi = new Cat("pipi");
18         mimi.info(); 
19         pipi.info();
20     }
21 }

 1 public class Cat {
 2     private  int sid = 0;
 3     private String name; 
 4     int id;
 5     Cat(String name) {
 6         this.name = name;  
 7         id = sid++;
 8     }
 9     public void info(){
10         System.out.println
11                ("My name is "+name+" No."+id);
12     }
13     public static void main(String arg[]){
14 
15        // Cat.sid = 100;
16         Cat mimi = new Cat("mimi");
17         Cat pipi = new Cat("pipi");
18         mimi.info(); 
19         pipi.info();
20     }
21 }