“Each Pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over,without ever doing the same thing twice.”

- Christopher Alexander

A pattern has four essential elements:

• The pattern name that we use to describe a design problem,
• The problem that describes when to apply the pattern,
• The solution that describes the elements that make up the design, and
• The consequences that are the results and trade-offs of applying the pattern.

Design patterns are descriptions of communicating objects and classes that are customized to solve a general design problem in a particular context.

I’m going to learn the following pattern in this year.

From July 2010 to Dec 2010.

Interface Patterns:

• Adapter
• Facade
• Composite
• Bridge

Responsibility Patterns:

• Singleton
• Observer
• Mediator
• Proxy
• Chain of Responsibility
• Fly weight

Operation Patterns:

• Template Method
• State
• Strategy
• Command
• Interpreter

Extension Patterns

• Decorator
• Iterator
• Visitor

Here’s a template to describe a design pattern:

• Pattern Name and Classification
• Intent
• Also Known As
• Motivation(Problem, Context)
• Applicability(Solution)
• Structure(a detailed specification of structural aspects)
• Participants, Collaborations(Dynamics)
• Implementation
• Example
• Known Uses
• Consequences
• Known Uses

Reference Books:

“Design Pattern In Java” as a reference book.

Steven John Metsker (Author), William C. Wake (Author)

“C# 3.0 Design Pattern

Judith Bishop (Author)