Biến

public class Student{
   // Bien instance nay la nhin thay cho bat ky lop con nao.
   public String ten;

   // Bien hocphi la chi nhin thay cho lop Student.
   private double hocphi;

   // Bien ten duoc gan trong constructor.
   public Student (String tenSV){
      ten = tenSV;
   }

   // Bien hocphi duoc gan mot gia tri.
   public void setHocPhi(double hp){
      hocphi = hp;
   }

   // Phuong thuc nay in chi tiet ve Student.
   public void inThongTin(){
      System.out.println("Ho va ten: " + ten );
      System.out.println("Hoc phi: " + hocphi);
   }

   public static void main(String args[]){
      Student sv1 = new Student("Do Van Khai");
      sv1.setHocPhi(4000);
      sv1.inThongTin();
   }
}