Draw an inheritance hierarchy for students at a university similar to the hierarchy shown in Fig. 9.2. Use Student as the superclass of the hierarchy, then extend Student with classes Undergraduate Student and Graduate Student. Continue to extend the hierarchy as deep (i.e., as many levels) as possible. For example, Freshman, Sophomore, Junior and Senior might extend Undergraduate Student, and Doctoral Student and Masters Student might be subclasses of Graduate Student.
After drawing the hierarchy, discuss the relationships that exist between the classes.