Design patterns are recurring solutions to recurring problems in software architecture.
The following are the three main categories of design patterns:
- Creational Patterns: Creational patterns provide ways to instantiate single objects or group of related objects.
- Structural Patterns: Structural patterns provide a way to define relationships among classes and objects.
- Behavioral Patterns: Behavioral Patterns define ways of communication among classes and objects.
The name of a patterns is in one of the categories.
Creational Patterns
- Abstract Factory: Creates an instance of several families of classes
- Builder: Separates object construction from its representation
- Factory Method: Creates an instance of several derived classes
- Prototype: A fully initialized instance to be copied or cloned
- Singleton: A class in which only a single instance can exist
Structural Patterns
- Adapter: Match interfaces of various classes.
- Bridge: Separates an object's interface from its implementation.
- Composite: A tree structure of simple and composite objects.
- Decorator: Add responsibilities to objects dynamically.
- Façade: A single class that represents an entire subsystem.
- Flyweight: A fine-grained instance used for efficient sharing.
- Proxy: An object representing another object.
Behavioral Patterns
- Mediator: Defines simplified communication among classes.
- Memento: Capture and restore an object's internal state.
- Interpreter: A way to include language elements in a program.
- Iterator: Sequentially access the elements of a collection.
- Chain of Resp: A way of passing a request among a chain of objects.
- Command: Encapsulates a command request as an object.
- State: Alter an object's behavior when its state changes.
- Strategy: Encapsulates an algorithm inside a class.
- Observer: A way of notifying a change to a number of classes.
- Template Method: Defers the exact steps of an algorithm to a subclass.
- Visitor: Defines a new operation to a class without change.