|
|
|
|
|
|
|
Some benefits of data abstraction disappear if you write methods that include direct instance-variable accesses or assignments.
If, for example, you decide to switch from a minutes-based
definition to an hours-based definition, then Java no longer can
compile any expression that attempts to access the minutes instance
variable directly. On the other hand, if you prevent direct access to the
minutes instance variable, no one can accidentally come to rely on
expressions that include such access.