Introduction to Design Patterns

Introduction to Design Patterns⌘

• A design pattern is a formal way of documenting a solution to a design problem in a particular field of expertise - it provides solution to common software design problems.
• The idea was introduced by the architect Christopher Alexander in the field of architecture and has been adapted for various other disciplines, including computer science.

GoF - Gang of Four ⌘

Erich Gamma, Richard Helm, Ralph Johnson, John Vlissides, Design patterns : elements of reusable object-oriented software

GoF Design Patterns ⌘

• Creational Patterns - how to create objects
  • Abstract Factory
  • Builder
  • Factory Matehod
  • Prototype
  • Singleton
• Structural Patterns - how to create structures of objects
  • Adapter
  • Bridge
  • Composite
  • Decorator
  • Facade
  • Flyweight
  • Proxy

GoF Design Patterns ⌘

• Behavioural Patterns - how to describe communication between objects
  • Chain of Responsibility
  • Command
  • Interpreter
  • Iterator
  • Mediator
  • Memento
  • Observer
  • State
  • Strategy
  • Template Method
  • Visitor

GoF Patterns Examples⌘

• http://www.blackwasp.co.uk/GofPatterns.aspx
• http://www.blackwasp.co.uk/Observer.aspx
• http://www.gofpatterns.com/design-patterns/module2/why-use-design-patterns-quiz.php