The Object-Oriented Thought Process, Fourth Edition

Identifying the Public Interfaces

It should be clear by now that perhaps the most important issue when designing a class is to keep the public interface to a minimum. The entire purpose of building a class is to provide something useful and concise. On page 109 of their book Object-Oriented Design in Java, Gilbert and McCarty state that “the interface of a well-designed object describes the services that the client wants accomplished.” If a class does not provide a useful service to a user, it should not have been built in the first place.

The Minimum Public Interface

Providing the minimum public interface makes the class as concise as possible. The goal is to provide the user with the exact interface to do the job right. If the public interface ...