Stephens' C# Programming with Visual Studio® 2010 24-Hour Trainer

section iii

Program Statements

The lessons in Section II focused on working with variables. They explained how to declare

variables, set their values, and perform calculations.

Those techniques let you do some fairly complex things, but they’re still relatively straight-

forward things that you could do yourself by hand if you really had to. For example, you could

easily calculate line item totals, sales tax, shipping, and a grand total for a purchase order.

With what you know so far, you really can’t write a program that takes full advantage of the

computer’s power. You can’t make the program add up an unknown number of values stored in

a

ListBox, perform the same task (such as calculating an account balance) for thousands of cus-

tomers, or take different actions depending on the user’s inputs. You can’t even write a program

that can tell if the user entered “seventy-eight” in a

TextBox that should contain a number.

The lessons in this section explain how to perform these kinds of tasks. They explain ways

you can make a program take different courses of action depending on circumstances, repeat

a set of actions many times, break code into manageable pieces to make it easier to write and

debug, and handle unexpected errors. After you finish reading these chapters, you’ll be able to

write applications that are much more powerful than those you can write now.

LESSON 18:  Making Choic ...