Summary

Visual Basic offers a fully object-oriented language with all the capabilities you would expect. This chapter described the basic concepts behind classes and objects, as well as the separation of interface from implementation and data.

The chapter introduced the System.Object class and explained how this class is the base class for all classes in .NET. You were then introduced to concepts such as Value and Reference types as well as the implementation for primitive types. The chapter looked at most of the core primitive types available in Visual Basic and how to convert between types.

You have learned how to use the Class keyword to create classes, and how those classes can be instantiated into specific objects, each one an instance of the class. These objects have methods and properties that can be invoked by the client code, and can act on data within the object stored in member or instance variables.

You also explored some more advanced concepts, including method overloading, shared or static variables and methods, and the use of delegates and lambda expressions.

The next chapter continues the discussion of object syntax as you explore the concept of inheritance and all the syntax that enables inheritance within Visual Basic. You will also walk through the creation, implementation, and use of multiple interfaces — a powerful concept that enables objects to be used in different ways, depending on the interface chosen by the client application.

Also covered in the next chapter is a discussion of objects and object-oriented programming, applying all of this syntax. It explains the key object-oriented concepts of abstraction, encapsulation, polymorphism, and inheritance, and shows how they work together to provide a powerful way to design and implement applications.