Every developer strives to write maintainable, readable, and reusable code. Code structuring becomes more important as applications become larger. Design patterns prove crucial to solving this challenge - providing an organization structure for common issues in a particular circumstance.
Design patterns can be broken down into a number of different categories. In this section we’ll review three of these categories and briefly mention a few examples of the patterns that fall into these categories before exploring specific ones in more detail.
Creational design patterns focus on handling object creation mechanisms where objects are created in a manner suitable for the situation we're working in. The basic approach to object creation might otherwise lead to added complexity in a project whilst these patterns aim to solve this problem by controlling the creation process.
Some of the patterns that fall under this category are: Constructor, Factory, Abstract, Prototype, Singleton and Builder.
Structural patterns are concerned with object composition and typically identify simple ways to realize relationships between different objects. They help ensure that when one part of a system changes, the entire structure of the system doesn't need to do the same. They also assist in recasting parts of the system which don't fit a particular purpose into those that do.
In other words, Structural patterns are used for object makup.
Patterns that fall under this category include: Decorator, Facade, Flyweight, Adapter and Proxy.
Behavioral patterns focus on improving or streamlining the communication between disparate objects in a system.
Some behavioral patterns include: Iterator, Mediator, Observer and Visitor.