Design Patterns Explained

26 Part I An Introduction to Object-Oriented Software Development
in Java as they are in C++. In C++, it is common for an object’s
destructor also to destroy other objects that are used only by this
object.
Summary
In this chapter In this chapter, I have shown how object orientation helps us minimize
consequences of shifting requirements on a system and how it
contrasts with functional decomposition.
Table 1-3 Object-Oriented Concepts
Concept Review
Functional
decomposition
Changing
requirements
I covered a number of the essential concepts in object-oriented programming
and have introduced and described the primary terminology.
These are essential to understanding the concepts in the rest
of this book. (See Tables 1-3 and 1-4.)
Structured programmers usually approach program design with functional
decomposition. Functional decomposition is the method of breaking down
a problem into smaller and smaller functions. Each function is subdivided
until it is manageable.
Changing requirements are inherent to the development process. Rather
than blaming users or ourselves about the seemingly impossible task of
getting good and complete requirements, we should use development
methods that deal with changing requirements more effectively.
Objects Objects are defined by their responsibilities. Objects simplify the tasks of
programs that use them by being responsible for themselves.
Constructors and
destructors
An object has special methods that are called when it is created and
deleted. These special methods are:
Constructors, which initialize or set up an object.
Destructors, which clean up an object when it is deleted.
All object-oriented languages use constructors and destructors to help
manage objects.