In software development a Software Design Pattern is a reusable solution to commonly recurring problems. A software design pattern is a description or template used to solve a problem that can be used in many different situations.
In 1994, the so called Gang Of Four (GOF) published their book Design Patterns: Elements of Reusable Object-Oriented Software in which they presented a catalog of simple and succinct solutions to commonly occurring design problems.
The book captured 23 Patterns that enabled software architects to create flexible, elegant and ultimately reusable design patterns without having to rediscover or reinvent the design solutions for themselves.
Through a series of blog posts on garywoodfine.com I will discuss these patterns and more on how C# .net core developers can implement these patterns in cross platform .net core software solutions.
Software Design patterns are typically categorised into three groups.
| Creational Patterns | |
|---|---|
| Simple Factory | interfaces for creating objects without exposing the object creation logic |
| Factory Method | Creates an instance of several derived classes |
| Abstract Factory | Creates an instance of several families of classes |
| Builder | Separates object construction from its representation |
| Prototype | A fully initialized instance to be copied or cloned |
| Singleton | A class of which only a single instance can exist |
| Structural Patterns | |
|---|---|
| Adapter | Match interfaces of different classes |
| Bridge | Separates an object’s interface from its implementation |
| Composite | A tree structure of simple and composite objects |
| Decorator | Add responsibilities to objects dynamically |
| Facade | A single class that represents an entire subsystem |
| Flyweight | A fine-grained instance used for efficient sharing |
| Proxy | An object representing another object |
| Behavioral Patterns | |
|---|---|
| Chain of Responsibility | A way of passing a request between a chain of objects |
| Command | Encapsulate a command request as an object |
| Interpreter | A way to include language elements in a program |
| Iterator | Sequentially access the elements of a collection |
| Mediator | Defines simplified communication between classes |
| Memento | Capture and restore an object's internal state |
| Observer | A way of notifying change to a number of classes |
| State | Alter an object's behavior when its state changes |
| Strategy | Encapsulates an algorithm inside a class |
| Template Method | Defer the exact steps of an algorithm to a subclass |
| Visitor | Defines a new operation to a class without change |
