In our last chapter, we explored the concepts of object-oriented programming, and worked through the process of building an application that conformed to object-oriented design principles. The Gang of Four (GoF) design patterns can be broken down into three main groups. The first of these groups is named Creational patterns, and covers numerous ways of creating objects. The second of these groups is named Structural patterns, and describe methods of designing object hierarchies that work together to achieve encapsulation and loose coupling. The third of these groups is named Behavioral patterns, and are designed to cover the behavior of a group of objects together in order to achieve certain goals. Over time, these patterns have sparked a wider interest in finding the simplest and best solutions for a wide range of programming problems.
As systems have become...
