Summary
In this chapter, we presented one idiom, the simple factory, and four patterns – the Factory Method pattern, the Abstract Factory pattern, the Object Pool pattern, and the Singleton pattern.
All of these patterns are classified as Creational patterns. This means they govern the creation of objects by encapsulating the creation logic in a structure that is more flexible than using strictly concrete objects with the new keyword.
The Factory Method pattern is what most people think of when they hear “factory pattern.” Using it entails abstracting creation logic into a factory class called a creator. The creator object is defined by an interface to maximize flexibility. We also create an interface for the objects the factory is producing. We call this the product. Each factory creator class is responsible for a subset of all the products in your program.
The Abstract Factory pattern involves creating families of objects that organically go together...