Object-Oriented Design Heuristics

Chapter 8. Class-Specific Data and Behavior

Introduction to Class-Specific Versus Object-Specific Data and Behavior

When teaching an object-oriented design course, I often ask the question, “Is an object required when you wish to send a message?” Invariably, the response is “Of course, messages are sent to objects.” Since the constructor of a class is one of its messages, how does one build the first object? It is clear that the constructor is a different sort of message. It does not require an object before it can be sent. (In the case of C++, the constructor is considered a normal message sent to an object that the standard allocator has created. For the purpose of this discussion, I consider my use of the term “constructor” to include standard ...