  class Student
    {
         int stu_code;                               
         String stu_name;                            
         int deptCode; 
         public Student()                          
         {
             stu_name=" ";                          
             stu_code=10011;                        
             deptCode = 11;                         
         }
         protected Student(String name,int sCode,int dCode)  
         {
             stu_name=name;                         
             stu_code= sCode;                        
             deptCode =dCode;                       
         }
         public static void main(String[] args)             
         {
           Student stu1 ;                     //һstu1
           stu1 = new Student();               //ʼstu1
           stu1.stu_name = "";
           //ʼstu2
           Student stu2 = new Student("",10012,12);             
Student stu3 = stu1;                //stu3ָѴڵĶ
           System.out.println(stu1 == stu3);
           System.out.println(stu2.equals(stu1));           
         }
   }
