Chapter 2 Design Patterns and Principles 📜 Contents 📜: 🧠 2.1 Designing an Interface 🧠 2.2 Introducing Functional Programming 🧠 2.3 Implementing Polymorphism 🧠 2.4 Understanding Design Principles 🧠 2.5 Working with Design Patterns 📝Revision Notes ✅ Review Questions