Master Design Patterns & SOLID Principles in C# - Full OOP Course for Beginners

This comprehensive beginner‑friendly course teaches fundamental OOP concepts such as inheritance, composition, encapsulation, abstraction, the difference between composition and inheritance, and the fragile base class problem. It covers Unified Modeling Language (UML) for visualizing class relationships, the five SOLID principles, and all 23 Gang of Four design patterns. Practical code examples are available in a GitHub repository, and a book and cheat sheet provide additional resources. The course begins with an introduction at 0:00:00, covers course contents at 0:00:33, discusses Gang of Four design patterns at 0:01:34, explains what design patterns are and why to learn them at 0:02:39, outlines prerequisites at 0:05:38, introduces the instructor at 0:06:57, mentions the book version at 0:07:32, shows the code repository at 0:08:19, and demonstrates setup at 0:08:49. It then delves into OOP concepts: encapsulation at 0:12:19, abstraction at 0:12:42, inheritance at 0:25:48, polymorphism at 0:30:52, coupling at 0:36:40, composition at 0:45:04, composition vs inheritance at 0:55:17, and the fragile base class problem at 0:58:11. UML is covered at 1:01:00, SOLID principles are introduced at 1:05:24, and each principle is explored in detail from 1:14:01 to 1:54:10. Design patterns are introduced at 2:04:56, with behavioural patterns such as Memento, State, Strategy, Iterator, Command, Template Method, Observer, Mediator, Chain of Responsibility, Visitor, and Interpreter covered between 2:07:37 and 7:06:29. Structural patterns including Composite, Adapter, Bridge, Proxy, Flyweight, Facade, and Decorator are discussed from 7:40:32 to 9:27:13. Creational patterns such as Prototype, Singleton, Factory Method, Abstract Factory, and Builder are presented from 9:58:50 to 11:46:29, concluding the course at 11:46:29.