software design patterns

There are three types of software design patterns:

#1: Creational These patterns deal with creation of objects in such a way that they can be de-coupled from their implementation. They are all about class instantiation.

Factory Abstract Factory Builder Prototype Singleton

#2: Structural These patterns deal with composition of different object structures. They are all about class and Object composition.

Adapter Bridge Composite Facade Proxy Decorater FlyWeight

#3: Behavioral These patterns deal with communication between objects. They are all about classes object communication.

Chain of Responsibility: Passes a request among a list or chain of objects.

Command: Wraps a request under an object as a command and passed to invoker object.

Interpreter: Implements an expression interface to interpret a particular context.

Iterator: Provides a way to access the elements of a collection object in sequential manner without knowing its underlying structure.

Mediator: Allows multiple objects to communicate with each other’s without knowing each other’s structure.

Memento: Capture the current state of an object and store it in such a manner that it can be restored at a later time without breaking the rules of encapsulation.

Observer: Allows an object (subject) to publish changes to its state and other objects (observer) that depend upon that object are automatically notified of any changes to the subject's state.

State: Alters the behavior of an object when it’s internal state changes.

Strategy: Allows a client to choose an algorithm from a family of algorithms at run-time and gives it a simple way to access it.

Visitor: Creates and performs new operations onto a set of objects without changing the object structure or classes.

Template Method: Defines the basic steps of an algorithm and allow the implementation of the individual steps to be changed.