Beginning Programming with C++ For Dummies®

Chapter 8. Debugging Your Programs, Part I

In This Chapter

• Avoiding introducing errors needlessly

• Creating test cases

• Peeking into the inner workings of your program

• Fixing and retesting your programs

You may have noticed that your programs often don't work the first time you run them. In fact, I have seldom, if ever, written a nontrivial C++ program that didn't have some type of error the first time I tried to execute it.

This leaves you with two alternatives: You can abandon a program that has an error, or you can find and fix the error. I assume that you want to take the latter approach. In this chapter, I first help you distinguish between types of errors and how to avoid errors in the first place. Then you get to find and eradicate two bugs that originally plagued the Conversion program in Chapter 3.

Identifying Types of Errors

Two types of errors exist — those that C++ can catch on its own and those that the compiler can't catch. Errors that C++ can catch are known as compile-time or build-time errors. Build-time errors are generally easier to fix because the compiler points you to the problem, if you can understand what the compiler's telling you. Sometimes the description of the problem isn't quite right (it's easy to confuse a compiler), but you start to understand better how the compiler thinks as you gain experience.

Errors that C++ can't catch don't show up until you try to execute the program during the process known as unit testing. During unit testing, you execute your program ...