OOP Design Patterns and Anti-Patterns: What Works and What Fails

Core Technical Concepts/Technologies Discussed:

• Object-Oriented Programming (OOP)
• Design Patterns (Creational, Structural, Behavioral)
• Anti-patterns
• SOLID Principles
• UML Diagrams

Main Points:

1. OOP Fundamentals:

   • Encapsulation, inheritance, polymorphism, and abstraction as core OOP concepts.
   • SOLID principles (Single Responsibility, Open-Closed, Liskov Substitution, Interface Segregation, Dependency Inversion) for maintainable design.

2. Design Patterns:

   • Creational: Factory, Singleton, Builder (object creation flexibility).
   • Structural: Adapter, Decorator, Facade (object composition and relationships).
   • Behavioral: Observer, Strategy, Command (object communication and responsibility delegation).

3. Anti-patterns:

   • God Object: Monolithic class violating Single Responsibility.
   • Spaghetti Code: Poorly structured, tightly coupled logic.
   • Circular Dependency: Mutual dependencies hindering modularity.

4. Implementation Examples:

   • Singleton: Ensures single instance via private constructor and static method.
   • Observer: Subject notifies observers of state changes (e.g., event systems).

Key Takeaways:

1. Use design patterns to solve recurring problems but avoid over-engineering.
2. Anti-patterns highlight common pitfalls; refactor them early.
3. SOLID principles guide scalable, maintainable OOP design.
4. Favor composition over inheritance for flexibility.
5. UML diagrams help visualize patterns and relationships.

Limitations/Further Exploration:

• Patterns may introduce complexity if misapplied.
• Context matters: Not all patterns fit every scenario.
• Explore modern alternatives (e.g., functional programming concepts).