Section 4.1. Introduction

4.1. Introduction

We introduced the basic terminology and concepts of object-oriented programming in Section 1.9. In Chapter 3, you began to use those concepts to create simple applications that displayed messages to the user, obtained information from the user, performed calculations and made decisions. One common feature of every application in Chapter 3 was that all the statements that performed tasks were located in method Main, in a module. Many of the applications you develop in this book will consist of one or more classes, each containing one or more methods. These classes will then be used in the module that contains Main. Industry applications can contain hundreds, or even thousands, of classes. In this chapter, we present a simple framework for organizing object-oriented applications in Visual Basic.

First, we motivate the notion of classes with a real-world example. Then we present five complete working applications to demonstrate creating and using your own classes. These examples begin our integrated case study on developing a grade-book class that instructors can use to maintain student test scores. This case study is enhanced over the next several chapters, culminating with the version presented in Chapter 8, Arrays.