Visual Basic .NET now supports class inheritance. VB6 supported interface inheritance, and VB .NET still does. Inheritance and implementation of interfaces have changed in subtle, grammatically different ways. However, the biggest change is the new support for class inheritance. When Microsoft says that Visual Basic .NET is a first-class language, one of the things the company is clearly referring to is class inheritance. Inheritance is a very powerful tool that will help us build more powerful applications.
The general guidelines provided in this chapter will help you decide when to use class inheritance and when to implement interfaces, as well as how to choose between using abstract classes and interfaces. This chapter also demonstrated how to create derived classes and use access modifiers to specify abstract classes and methods and how to support encapsulation and information hiding.