Creational:
Abstract Factory: Creates concrete instances of classes.Singleton:
Creates a single instance of a class and ensures there is only one instance in the system.
Class contruction: Keep a private member in the class and let the constructor initialize it only if that member is null.
Application: System resources; there is only one printer in the system and we must access it thru singleton pattern.
Structural:
Facade: Represents an entire system of subclasses.
Proxy: Not the real object itself, just represents the real object.
Behavioral:
Command:
A command request is encapsulated as an object.
Observer:
Notifies changes to classes.
Application: Error logging.
Web Design specific:
MVC (Model-View-Controller):
Complete separation of the;
model (database),
view (page view) and
controller (business logic).
