Playing Card Backside - Data Areas

The back side, on the other hand, can be used to record internal representation decisions concerning the component. For example, we might decide that the suit and rank will be encoded as integer variables, while the face up status is held by a boolean variable. Since these are not part of the interface, they need not be seen by users of the abstraction, but only by the implementor.

[audio] [real] Text to accompany slide7, in Chapter 3 of An Introduction to Object-Oriented Programming