Software Best Design Patterns

Quick glance at design patterns, hand

Pattern	Example	Reason
Momento	Redo-undo
Prototype	Deep copy/shallow copy
Façade	Hides everything; one interface for all of the functionality; Complex subsystem
Factory	Create views for different types of documents;(html, pdf, doc, xml, etc)	Centralized creation of objects
	create database connection for diff types of databases (sql, oracle, mysql, etc)	Decouple concrete classes from clients
Abstract Factory	Factory of factories

Pattern	Example	Reason
Builder	Report builder, header, footer, type (pdf, html, excel)	Separates construction from representation
Command	Commands from the file menu; New, Open, Print, Exit
Iterator	Iterates through a list of objects
Chain of responsibility	Context help menu, help request goes to all of the controls on the windows forms; and whoever is responsible to provide the help, provides the help	Every objects gets a chance to perform its function. More: http://izlooite.blogspot.ae/2009/04/design-pattern-chain-of-responsibility.html

Pattern	Example	Reason
Unit of work	Manages a business transaction (That may contain list of transactions)	For instance, getting user input into a wizard.
Producer-Consumer Patter	A server getting millions of connections. All pushed into a queue, and processed one by one (or multiple, depending on server architecture).
Repository Pattern	Usually used with an ORM, that takes the responsibility of performing CRUD, by providing business methods
Unified Design	Multi device infrastructure	http://izlooite.blogspot.ae/2011/07/how-to-think-unified-design-for-multi.html

 Happy designing!