created 12/13/98; revised: 09/23/99, 01/21/00, 07/14/02, 01/19/06, 11/11/08, 07/31/14
So far, the objects that we have designed have instance variables that are visible outside of the objects. Code that holds a reference to an object can change the object's instance variables. This can lead to problems.
A better design enforces encapsulation, where
an object's instance variables are
visible only to the object's own methods.
Code outside of the object cannot directly access these variables.
This chapter discusses how to use the private
visibility modifier
to do this.
private
and the public
visibility modifiersCheckingAccount
classShould a bank control who has access to your checking account?