Design Patterns: A Developer's Guide to Common Solutions

Introduction

Design patterns are reusable solutions to common problems in software design. This guide covers the most important patterns and their practical applications.

Creational Patterns

• Singleton: Ensure a class has only one instance
• Factory Method: Create objects without specifying exact class
• Abstract Factory: Create families of related objects
• Builder: Construct complex objects step by step
• Prototype: Create new objects by cloning existing ones

Structural Patterns

• Adapter: Make incompatible interfaces work together
• Bridge: Separate abstraction from implementation
• Composite: Compose objects into tree structures
• Decorator: Add responsibilities to objects dynamically
• Facade: Provide a simplified interface

Behavioral Patterns

• Observer: Define one-to-many dependencies
• Strategy: Define a family of algorithms
• Command: Encapsulate a request as an object
• State: Allow an object to alter its behavior
• Template Method: Define skeleton of an algorithm

Best Practices

• Choose patterns based on problem context
• Don't over-engineer solutions
• Consider maintainability
• Document pattern usage

Conclusion

Design patterns are powerful tools when used appropriately, but they should be applied with careful consideration of the specific problem context.