Summary

This chapter demonstrated how Visual Basic enables you to create and work with classes and objects. Visual Basic provides the building blocks for abstraction, encapsulation, polymorphism, and inheritance.

You’ve learned how to create both simple base classes as well as abstract base classes. You’ve also explored how you can define formal interfaces, a concept quite similar to an abstract base class in many ways.

You also walked through the process of subclassing, creating a new class that derives both interface and implementation from a base class. The subclass can be extended by adding new methods or altering the behavior of existing methods on the base class.

By the end of this chapter, you’ve seen how object-oriented programming flows from the four basic concepts of abstraction, encapsulation, polymorphism, and inheritance. The chapter provided basic information about each concept and demonstrated how to implement them using Visual Basic.

By properly applying object-oriented design and programming, you can create very large and complex applications that remain maintainable and readable over time. Nonetheless, these technologies are not a magic bullet. Improperly applied, they can create the same hard-to-maintain code that you might create using procedural or modular design techniques.

It is not possible to fully cover all aspects of object-oriented programming in a single chapter. Before launching into a full-blown object-oriented project, we highly recommend looking at other books specifically geared toward object-oriented design and programming.