Behavioral Patterns

Algorithms and the assignment of responsibilities between objects.

Table of Contents

• Chain of Responsibility: Lets you pass requests along a chain of handlers.
• Command: Turns a request into a stand-alone object that contains all information about the request.
• 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: Lets you traverse elements of a collection without exposing its underlying representation.
• Mediator: Lets you reduce chaotic dependencies between objects.
• Memento: Lets you save and restore the previous state of an object without revealing the details of its implementation.
• Observer: Lets you define a subscription mechanism to notify multiple objects about any events that happen to the object they’re observing.
• State: Lets an object alter its behavior when its internal state changes.
• Strategy: Lets you define a family of algorithms, put each of them into a separate class, and make their objects interchangeable.
• Template Method: Defines the skeleton of an algorithm in the superclass but lets subclasses override specific steps of the algorithm without changing its structure.
• Visitor: Lets you separate algorithms from the objects on which they operate.