Behavioral Design Patterns
Behavioral design patterns focus on how objects interact and communicate with each other. They help define clear communication patterns, making systems more flexible and maintainable.
List of Behavioral Design Patterns
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Observer Pattern
Defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.- Example: Subscription model for a news website.
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Strategy Pattern
Defines a family of algorithms, encapsulates each one, and makes them interchangeable.- Example: Different sorting algorithms in a data processing application.
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Command Pattern
Encapsulates a request as an object, allowing for parameterization of clients with queues, requests, and operations.- Example: Undo/redo functionality in a text editor.
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State Pattern
Allows an object to change its behavior when its internal state changes, appearing to change its class.
Summary Table
| Pattern | Intent | Example Use Case |
|---|---|---|
| Observer | Notify dependents of state changes | News subscription, GUIs |
| Strategy | Select algorithm at runtime | Payment methods, sorting |
| Command | Encapsulate requests as objects | Undo/redo, macro recording |
| State | Change behavior based on internal state | TV on/off, workflow engines |