Behavioral design patterns

Behavioral design patterns increase communication flexibility between objects based on the specific ways they interact with each other. Here, creational patterns mostly describe a moment in time during creation, structural patterns describe a more or less static structure, and behavioral patterns describe a process or flow. They simplify this flow and make it more understandable.

The main features of behavioral design patterns are as follows:

• What is being described is a process or flow
• The flows are simplified and made understandable
• They accomplish tasks that would be difficult or impossible to achieve with objects

In this book, we will focus our attention on the following behavioral design patterns:

• The value object design pattern
• The null object design pattern
• The strategy design pattern
• The command design pattern
• The chain of responsibility design pattern
• The interpreter design pattern
• The iterator design pattern
• The mediator design pattern
• The memento design pattern
• The observer design pattern
• The state design pattern
• The template method design pattern
• The visitor design pattern

The following subsections will give brief definitions of the aforementioned behavioral design patterns.