Pattern List

Creational patterns:

Abstract factory:

Provide an interface for creating families of related or dependent objects without specifying their concrete classes.

Builder:

Separate the construction of a complex object from its representation allowing the same construction process to create various representations.

Factory method:

Define an interface for creating a single object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses.

Lazy Loading

Tactic of delaying the creation of an object, the calculation of a value, or some other expensive process until the first time it is needed.

Prototype

Specify the kinds of objects to create using a prototypical instance, and create new objects by copying this prototype.

Singleton

Ensure a class has only one instance, and provide a global point of access to it.

Structural patterns:

Adapter or Wrapper or Translator:

Convert the interface of a class into another interface clients expect. An adapter lets classes work together that could not otherwise because of incompatible interfaces.

Bridge

Decouple an abstraction from its implementation allowing the two to vary independently.

Composite

Compose objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly.

Decorator

Attach additional responsibilities to an object dynamically keeping the same interface. Decorators provide a flexible alternative to sub classing for extending functionality.

Facade

Provide a unified interface to a set of interfaces in a subsystem. Facade defines a higher-level interface that makes the subsystem easier to use.

Flyweight

Use sharing to support large numbers of similar objects efficiently.

Proxy

Provide a surrogate or placeholder for another object to control access to it. (Also used in lazy loading)

Behavioural patterns:

Chain of responsibility

Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it.

Command

Encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations.

Interpreter

Given a language, define a representation for its grammar along with an interpreter that uses the representation to interpret sentences in the language.

Iterator

Provide a way to access the elements of an aggregate object sequentially without exposing its underlying representation.

Mediator

Define an object that encapsulates how a set of objects interact. Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently.

Memento

Without violating encapsulation, capture and externalize an object's internal state allowing the object to be restored to this state later. Yes No N/A

Null object

Avoid null references by providing a default object.

Observer or Publish/subscribe

Define a one-to-many dependency between objects where a state change in one object results in all its dependents being notified and updated automatically.

State

Allow an object to alter its behaviour when its internal state changes. The object will appear to change its class.

Visitor

Represent an operation to be performed on the elements of an object structure. Visitor lets you define a new operation without changing the classes of the elements on which it operates.