# Gang of Four Design Patterns
# Creational Patterns
# Abstract Factory
Creational pattern
Abstract factory groups object factories that have a common theme, providing an interface for creating families of related or dependent objects without specifying their concrete classes
- Abstract factories are like "super factories" that create other factories
# Sources
- Abstract Factory Pattern | Object Oriented Design (opens new window)
- The Factory Design Pattern Explained by Example (opens new window)
# Builder
Creational pattern
Builder constructs complex objects by separating construction and representation.
# Factory Method
Creational pattern
Factory method creates objects without specifying the exact class to create. Also called the Virtual Constructor
# Sources
# Prototype
Creational pattern
Prototype creates objects by cloning an existing object
# Singleton
Creational pattern
Singleton restricts object creation for a class to only one instance
# Structural Patterns
# Adapter
Structural pattern
Adapter allows classes with incompatible interfaces to work together by wrapping its own interface around that of an already existing class
# Bridge
Structural pattern
Bridge decouples an abstraction from its implementation so that the two can vary independently.
# Composite
Structural pattern
Composite composes zero-or-more similar objects so that they can be manipulated as one object
# Decorator
Structural pattern
Decorator dynamically adds/overrides behavior in an existing method of an object
# Facade
Structural pattern
Facade provides a simplified interface to a large body of code
# Flyweight
Structural pattern
Flyweight reduces the cost of creating and manipulating a large number of similar objects
# Proxy
Structural pattern
Proxy provides a placeholder for another object to control access, reduce cost, and reduce complexity
# Behavioral Patterns
# Chain of Responsibility
Behavioral pattern.
Chain of responsibility delegates commands to a chain of processing objects.
# Command
Behavioral pattern.
Command creates objects which encapsulate actions and parameters.
# Interpreter
Behavioral pattern.
Interpreter implements a specialized language.
# Iterator
Behavioral pattern
Iterator accesses the elements of an object sequentially without exposing its underlying representation.
# Mediator
Behavioral pattern
Mediator allows loose coupling between classes by being the only class that has detailed knowledge of their methods.
# Memento
Behavioral pattern
Memento provides the ability to restore an object to its previous state (undo).
# Observe
Behavioral pattern
Observer is a publish/subscribe pattern which allows a number of observer objects to see an event.
# State
Behavioral pattern
State allows an object to alter its behavior when its internal state changes.
# Strategy
Behavioral pattern
Strategy allows one of a family of algorithms to be selected on-the-fly at runtime.
# Template
Behavioral pattern Template method defines the skeleton of an algorithm as an abstract class, allowing its subclasses to provide concrete behavior.
# Visitor
Behavioral pattern
Visitor separates an algorithm from an object structure by moving the hierarchy of methods into one object.