Inheritance - Java - page 456

EXAMPLES
Suppose that HourlyEmployee is a derived class of Employee and that employeeObject
and hourlyEmployeeObject are created as follows:
Employee employeeObject = new Employee();
HourlyEmployee hourlyEmployeeObject = new HourlyEmployee();
Then:
employeeObject.getClass() == hourlyEmployeeObject.getClass()
returns false .
employeeObject instanceof Employee
returns true .
hourlyEmployeeObject instanceof Employee
returns true .
employeeObject instanceof HourlyEmployee
returns false .
hourlyEmployeeObject instanceof HourlyEmployee
returns true .
Self-Test Exercises
18. Redefine the method equals given in Display 7.10 using instanceof instead of
getClass() . Give the complete definition. Remember, we do not want you to
define equal s this way in your class definitions; this is just an exercise.
19. Redefine the equals method of the class HourlyEmployee (Display 7.3) so that it
has a parameter of type Object and follows the other guidelines we gave for an
equals method. Assume the definition of the method equals for the class
Employee has been changed to be as in Display 7.10. (Remember, you should use
getClass() , not instanceof .)