DesignPatterns.md

Design Patterns

---

Design patterns are standard solutions to common problems in software design. They represent best practices, providing a way to structure code in a way that's reusable, maintainable, and understandable. Patterns can be classified into three types: creational (for object creation), structural (for object relationships), and behavioral (for object interactions and responsibility distribution).

---

• Design Patterns
  • Before you begin studying design patterns
  • Gamma categorization
  • Patterns

Before you begin studying design patterns

Programming Basics & OOP

SOLID principle

Gamma categorization

---

Important The "Gamma categorization" refers to the classification of design patterns proposed in the book "Design Patterns: Elements of Reusable Object-Oriented Software" by Erich Gamma and others. It categorizes design patterns into three types:

• Creational Patterns
  • Deal with the creation (construction) of objects
  • Explicit (constructor) vs. implicit (DI, reflection, etc.)
  • Wholesale (single statement) vs. piecewise (step-by-step)
• Structural Patterns
  • Concerned with the structure (e.g., class members)
  • Many patterns are wrappers that mimic the underlying class’ interface
  • Stress the importance of good API design
• Behavioral Patterns
  • They are all different; no central theme

---

Patterns

Creational	Structural	Behavioral
🛠️ Builder	🔌 Adapter	🔗 Chain of Responsibility
🏭 Factory	🌉 Bridge	🔘 Command
🧬 Prototype	🌳 Composite	📖 Interpreter
🔐 Singleton	🎨 Decorator	🔄 Iterator
	🚪 Façade	🤝 Mediator
	🍃 Flyweight	📦 Memento
	🕵️ Proxy	0️⃣ Null Object
		👁️ Observer
		🔄 State
		💡 Strategy
		📜 Template Method
		🚶 Visitor

GPT4 was used to generate explanations.

Examples from the course:

Design Patterns in C# and .NET: Learn Solutions to Common Problems

Found on rutracker.org