Professional C# 7 and .NET Core 2.0, 7th Edition

4Object-Oriented Programming with C#

WHAT’S IN THIS CHAPTER?

• Types of inheritance
• Implementation inheritance
• Access modifiers
• Interfaces
• is and as Operators

WROX.COM CODE DOWNLOADS FOR THIS CHAPTER

The Wrox.com code downloads for this chapter are found at www.wrox.com on the Download Code tab. The source code is also available at https://github.com/ProfessionalCSharp/ProfessionalCSharp7 in the directory ObjectOrientation.

The code for this chapter is divided into the following major examples:

• VirtualMethods
• InheritanceWithConstructors
• UsingInterfaces

OBJECT ORIENTATION

C# is not a pure object-oriented programming language. C# offers multiple programming paradigms. However, object orientation is an important concept with C#, and it’s a core principle of all the libraries offered by .NET.

The three most important concepts of object-orientation are inheritance, encapsulation, and polymorphism. Chapter 3, “Objects and Types,” talks about creating individual classes to arrange properties, methods, and fields. When members of a type are declared private, they cannot be accessed from the outside. They are encapsulated within the type. This chapter’s focus is on inheritance and polymorphism.

The previous chapter also explains that all classes ultimately derive from the class System.Object. This chapter covers how to create a hierarchy of classes and how polymorphism works with C#. It also describes all the C# keywords related to inheritance.

TYPES OF INHERITANCE

Let’s ...