Behavioral Patterns

Behaviorall patterns are concerned with algorithms and the assignment of responsibilities between objects. They describe not just patterns of objects or classes but also the patterns of communication between them.

The GoF categorizes 11 patterns into behavioral patterns, which can be broadly divided into two categories:

Processing Patterns(Focusing on Algorithm Flow)

• Template Method Pattern: Defines the skeleton of an algorithm, deferring certain steps to subclasses.
• Strategy Pattern: Defines a family of algorithms that are interchangeable.
• Command Pattern: Encapsulates requests as objects, facilitating parameterization and queuing.
• Interpreter Pattern: Given a language, define its grammar and interpreter.
• Chain of Responsibility Pattern: Allows multiple objects to handle requests, forming a chain.
• State Pattern: Allows objects to change their behavior when their internal state changes.

Communication Patterns(Focusing on Object Relationships)

• Observer Pattern: Defines a one-to-many dependency, allowing multiple observers to automatically listen to a single topic.
• Iterator Pattern: Sequentially accesses aggregate objects without exposing their internal representation.
• Mediator Pattern: Encapsulates the interactions of a group of objects using a mediator object, avoiding mesh communication.
• Memento Pattern: Captures the internal state of an object for later recovery.
• Visitor Pattern: Define new operations that can be performed on elements without changing their classes.