C# 5.0 Programmer's Reference

Chapter 6 Methods

What’s in This Chapter

• Method declarations
• Optional and named parameters
• Method overloading
• Extension methods
• Lambda expressions
• Covariance and contravariance
• Asynchronous method execution

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Methods enable you to break an otherwise unwieldy chunk of code into manageable pieces. They enable you to extract code that you may need to use under more than one circumstance and place it in a single location where you can call it as needed.

This enables you to maintain and update the code in a single location. If you later need to modify the code, you need to do it only in one place, so you don’t need to keep multiple copies of the code synchronized.

Method Terminology

Methods that don’t return a value (have a void return type) are sometimes called subroutines, routines, procedures, or subprocedures. Methods that return a value are sometimes called functions.

This chapter describes methods and explains the syntax for declaring them. It also provides some tips for making methods more maintainable.

Method Declarations

In C# all methods must be inside a class. The syntax for creating a method follows:

«attributes» «accessibility» «modifiers» return_type name(«parameters»)
{
    code...
}

Many of these pieces of the declaration are similar ...