C++ All-in-One For Dummies, 4th Edition

Chapter 4

Building with Design Patterns

IN THIS CHAPTER

Understanding what design patterns are and how you can use them

Implementing an observer pattern

Building a mediator pattern

When you work as a developer, eventually you start to notice that you do certain things repeatedly. For example, when you need to keep track of how many instances of a certain class you create, you define a static property called something like int InstanceCount;, include a line that increments InstanceCount in the constructor, and include a line that decrements InstanceCount in the destructor. You make InstanceCount private and include a static method that retrieves the value, such as getInstanceCount().

Because you use it so often, it becomes a pattern. The first time you used it, you had to think about it — how to design and implement it. Now, you barely have to think about it; you just do it. Thus, it’s a design pattern that you use.

This chapter takes a practical look at design patterns that you use when creating applications. It helps you understand why using design patterns reduces development time, makes code less error prone, and improves application efficiency. The chapter delves just a bit ...