Chapter 23. The Factory Pattern

Design patterns are reusable programming solutions that have been used in various real-world contexts, and have proved to produce expected results. They are shared among programmers and continue being improved over time. This topic is popular thanks to the book by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides, titled Design Patterns: Elements of Reusable Object-Oriented Software.

Note

Gang of Four: The book by Erich Gamma, Richard Helm, Ralph Johnson, and John Vlissides is also called the Gang of Four book for short (or GOF book for even shorter).

Here is a quote about design patterns from the Gang of Four book:

A design pattern systematically names, motivates, and explains a general design that addresses a recurring design problem in object-oriented systems. It describes the problem, the solution, when to apply the solution, and its consequences. It also gives implementation hints and examples. The solution is a general arrangement of objects and...