Professional C# and .NET, 2021st Edition

5Operators and Casts

WHAT'S IN THIS CHAPTER?

• Operators in C#
• Implicit and explicit conversions
• Overloading standard operators for custom types
• Comparing objects for equality
• Implementing custom indexers
• User-defined conversions

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/OperatorsAndCasts.

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

• OperatorsSample
• BinaryCalculations
• OperatorOverloadingSample
• EqualitySample
• CustomIndexerSample
• UserDefinedConversion

All the projects have nullable reference types enabled.

The preceding chapters have covered most of what you need to start writing useful programs using C#. This chapter continues the discussion with essential language elements and illustrates some powerful aspects of C# that enable you to extend its capabilities. This chapter also covers information about using operators and extending custom types with operator overloading and custom conversion.

OPERATORS

C# supports the operators and expressions listed in the following table. In the table, the operators start with the highest precedence and go down to the lowest.

CATEGORY	OPERATOR
Primary	x.y x?.y f(x) a[x] x++ x-- x! x->y new typeof default checked unchecked delegate nameof sizeof delegate stackalloc
Unary	+x -x !x ...