YouthBirthday birth;
birth               = new Birthday( "Terry", 23 );

New Definition of YouthBirthday

Parents can accommodate children, but children can't accommodate parents. If you find this rule hard to remember, just think of yourself and your parents:

It is OK for you to go home and stay in your parent's house for a few days, but it's not OK for them to stay in your dorm room for a few days.

Now let us re-write YouthBirthday in order to show more about polymorphism. Say that you want two greeting() methods for YouthBirthday:

1. The parent's greeting() method.
   • This will be included by inheritance.
2. A method with the name of the sender as a parameter.
   • This will be an additional method―it will not override the parent's method.
   • In addition to what the parent's method does, this method will write out "How you have grown!! Love," followed by the name of the sender.

Here is a skeleton:

// Revised version
//
class YouthBirthday  extends Birthday

{
  public  YouthBirthday ( String r, int years )
  {
    super ( r, years )
  }

  // additional method---does not override parent's method
  public void greeting( ___________  ____________ )
  {
    super.greeting();
    System.out.println("How you have grown!!\n");
    System.out.println("Love, " + ___________ + "\n" );
  }
}