Few weeks ago, I commit to take an session about design pattern in my organization. As a matter of fact, I’m not a big fan of design pattern. However, I began dwell with design pattern, I found interesting on it. So I decided to write some posts on it. In this post, I just give an introduction about design pattern.
So what is design pattern?
Design Pattern are conceived by the 4 people who wrote the book "Design Patterns: Elements of Reusable Object-Oriented Software ". Design pattern is a proven ways to solve the particular problem while arising often writing software programs. Those problems are frequently encountered by the programmers, most probably when design the software. So there is no reinvent the well again. There are 23 solutions predefined by the above authors. Each problem has its own name also.
The ultimate goal:
There is no reinvent of solution for the 23 problems. Also the main benefit is maintainability of software. If you want to change something in the existing system it is so easy. The above are the main benefits of design pattern. These 23 design patterns are called Gang Of Four in general.
They are categorized into 3 types. They are: 1. Structural Pattern 2. Creational Pattern 3. Behavioral Patterns
The category name itself enough to explain, the purpose of each pattern. For example, Creational patterns are talk about the object creation. At the same time structural pattern described about code structure. Below are the 23 design patterns.
Creational Patterns:
- Abstract Factory
- Singleton Pattern
- Builder Pattern
- Factory Method Pattern
- Prototype Pattern
Structural Patterns:
- Flyweight Pattern
- Proxy Pattern
- Adapter Pattern
- Bridge Pattern
- Facade Pattern
- Composite Pattern
- Decorator Pattern
- Behavioral Patterns:
- Chain of Responsibility
- Observer Pattern
- Command Pattern
- Interpreter Pattern
- Iterator Pattern
- Visitor Pattern
- Template Pattern
- Strategy Pattern
- Memento Pattern
- Mediator Pattern
- State Pattern
