I am developing a AppointmentCalender as an assignment, part of the assignment was to write our own versions of the Date and Time class. I did this but I am confused as to whether I import the Date and Time classes or if I extend them. If I extend them how to I extend them within this hierarchy: Date Time Appointment AppointmentCalendar Do I say Public class Appointment extends Date, Time Public class AppointmentCalender extends Appointment I am not sure if you can or want to extend two classes? Gerald
A class can only extend one other class. If the assignment is to "write your own versions" of Date and Time (there really isn't a Time class, anyway; there's java.sql.Time, but this is actually just a trivial subclass of Date) then I suspect the professor wants you to, indeed, write your own versions -- not subclass the existing one(s). Regarding whether AppointmentCalendar should extend Appointment: ask yourself "Is an AppointmentCalendar a kind of Appointment?" If the answer is "yes" then it's appropriate to have AppointmentCalendar extend Appointment. If the answer is "no", then it's not, simple as that.