Chapter 29: Understanding Class Modules


Introducing class modules

Exploring some typical uses for class modules

Seeing examples that demonstrate some key concepts related to class modules

What is a Class Module?

For many VBA programmers, the concept of a class module is a mystery, even though this feature has been available in Visual Basic for many years — it was added to Excel beginning with Excel 97. The examples in this chapter may help to make this powerful feature less mysterious.

A class module is a special type of VBA module that you can insert into a VBA project. Basically, a class module enables the programmer (you) to create a new object class. As you should know by now, programming Excel really boils down to manipulating objects. A class module allows you to create new objects, along with corresponding properties, methods, and events.

cross_ref.eps Examples in previous chapters in this book use class modules. See Chapters 15, 18, 19, and 22.

At this point, you might be asking, “Do I really need to create new objects?” The answer is no. You don't need to, but you might want to after you understand some of the benefits of doing so. In many cases, a class module simply serves as a substitute for functions or procedures, but it could be a more convenient and manageable alternative. In other cases, however, you'll find that a class module is the only way to accomplish ...

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