public class Downcasting1
{
   public static void main(String[] args)
   {
      BankAccount x;             // x is a Base class variable

      CheckingAccount y;         // y and z are Derived class variables
      CheckingAccount z;


      /* -------------------------------------------------------
         Remember that:
            A derived class may have MORE variables/methods 
            than the base class !
         ------------------------------------------------------- */

      /* --------------------------------
         A legal downcasting scenario
         -------------------------------- */
      y = new CheckingAccount(343, "John", 2000.0);

      x = y;                    // Upcasting, allowed (discussed before wby)
                                // x references a CheckingAccount object

      z = (CheckingAccount) x;  // Downcasting, allowed because:
                                //    x references a CheckingAccount object
                                //    z is a CheckingAccount reference var.
                                // compatible
   }
}