Professional C# and .NET, 2021st Edition

2Core C#

WHAT'S IN THIS CHAPTER?

• Top-level statements
• Declaring variables
• Target-typed new expressions
• Nullable types
• Predefined C# data types
• Program flow
• Namespaces
• Strings
• Comments and documentation
• C# preprocessor directives
• Guidelines and coding conventions

CODE DOWNLOADS FOR THIS CHAPTER

The source code for this chapter is available on the book page at www.wiley.com. Click the Downloads link. The code can also be found at https://github.com/ProfessionalCSharp/ProfessionalCSharp2021 in the directory 1_CS/CoreCSharp.

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

• TopLevelStatements
• CommandLineArgs
• VariableScopeSample
• NullableValueTypes
• NullableReferenceTypes
• ProgramFlow
• SwitchStatement
• SwitchExpression
• ForLoop
• StringSample

All the sample projects have nullable reference types enabled.

FUNDAMENTALS OF C#

Now that you understand more about what C# can do, you need to know how to use it. This chapter gives you a good start in that direction by providing a basic understanding of the fundamentals of C# programming, which subsequent chapters build on. By the end of this chapter, you will know enough C# to write simple programs (though without using inheritance or other object-oriented features, which are covered in later chapters).

The previous chapter explained how to create a “Hello, World!” application using the .NET CLI tools. This chapter focuses on C# syntax. First, here's some general information on the syntax:

• Statements ...