In the book, the author writes the following:
[quote]For example, the officeAlarmCode property of BNREmployee should be private. The employee object needs to be able to access its alarm code, while
non-employee objects do not need access to the alarm code and should not have it.[/quote]
As far as I concern, even the officeAlarmCode property is non-private, instances of other class types still unable to access it, right?
Then why do we need the class extension in the first place?
Well hope anyone of you who are expertise enough in this matter to advise me.