Chapter 5. Subroutines and Functions

You will learn the following in this chapter:

• What subroutines and functions are available in Visual Basic .NET

• Why subroutines and functions are different from each other and when you should use one instead of the other

• How to pass subroutine and function arguments

Recall from Chapter 2, "The Basics of Object-Oriented Programming," that one of the breakthroughs in the early development of languages was the advent of the subroutine. In Chapter 2 you learned how subroutines simplify program structure by avoiding duplicate code for repetitive processes. Subroutines reduce program complexity and program size. This chapter examines both subroutines and functions in considerable detail. It also uses your understanding of lvalue and rvalue from Chapter 4, "Data Types and Numeric Variables," to demystify how information is passed to subroutines and functions.