Behavioral Design Patterns

Behavioral design patterns deal with communication between objects, what goes on between objects and how they operate together. These patterns focus on how objects can be composed to obtain new functionality.

There are several types of behavioral design patterns, including the chain of responsibility, command, interpreter, iterator, mediator, memento, observer, state, strategy, template method, and visitor patterns.

1. The chain of responsibility pattern allows a request to be passed through a chain of objects, with each object having the option to process the request or pass it on to the next object in the chain.
2. The command pattern encapsulates a request as an object, allowing you to parametrize other objects with different requests, queue or log requests, and support undoable operations.
3. The interpreter pattern implements a specialized language by using a defined grammar and representing the language in a tree-like structure.
4. The iterator pattern provides a way to access the elements of an object sequentially without exposing its underlying representation.
5. The mediator pattern allows you to define a separate object that encapsulates the interaction between a set of objects, reducing the dependencies between them.
6. The memento pattern captures and stores the state of an object, enabling restoration to that state later. It is used for undo/redo and rollback functionality.
7. The observer pattern allows objects to observe changes in the state of other objects, and be notified when these changes occur.
8. The state pattern allows an object to alter its behavior when its internal state changes, and can appear as if the object has changed its class.
9. The strategy pattern allows you to define a family of algorithms, and make them interchangeable within a client.
10. The template method pattern defines the steps of an algorithm and allows subclasses to provide implementation for one or more of these steps.
11. The visitor pattern separates an algorithm from an object structure by moving the hierarchy of methods into one object, and the implementation of these methods into another object.