Welcome to OOPS via C#. Below is the complete course list organized into sections. Click any lesson to open the full page. Follow lessons in chronological order for smooth learning.
Jump to: Introduction • Four Pillars • Core Concepts • Projects • Interview Prep
Section 1 — Introduction
This section covers the basics of OOP, why it matters, and initial C# examples.
- Lesson 1 — What is OOP?
What OOP is, benefits, and a simple C# class/object example. - Lesson 2 — Why OOP is Important in C#?
How OOP improves maintainability, reusability, and structure in C# projects. - Lesson 3 — Procedural vs OOP
A clear comparison using real-world and C# examples. - Lesson 4 — Real-World Analogy
Car, Bank Account, Student examples to understand OOP visually.
Section 2 — The Four Pillars of OOP
The foundation of OOP — encapsulation, abstraction, inheritance, and polymorphism.
- Lesson 5 — Encapsulation
Properties, getters/setters, and access modifiers. - Lesson 6 — Abstraction
Abstract classes and interfaces with real use cases. - Lesson 7 — Inheritance
Base/derived classes and when to use inheritance. - Lesson 8 — Polymorphism
Overloading, overriding, and virtual/override in C#.
Section 3 — Core Concepts in C#
Important building blocks of C# OOP programming.
- Lesson 9 — Classes & Objects
Syntax, fields, properties, and creating instances. - Lesson 10 — Constructors
Default, parameterized, and static constructors. - Lesson 11 — this vs base
Difference and usage in derived classes. - Lesson 12 — Access Modifiers
public, private, protected, internal explained. - Lesson 13 — Properties
Auto-properties, get/set, and backing fields. - Lesson 14 — Method Overloading
Compile-time polymorphism examples. - Lesson 15 — Method Overriding
Runtime polymorphism using virtual/override. - Lesson 16 — Abstract Class vs Interface
Key differences and when to use which. - Lesson 17 — Sealed Keyword
Preventing class inheritance. - Lesson 18 — Static vs Instance Members
Memory model + best practices.
Section 4 — Mini Projects
- Mini Project 1 — Student Management System
Classes for student, course, and enrollment. - Mini Project 2 — Banking System
Account hierarchy and transactions.
Section 5 — Interview Preparation
- Beginner Interview Questions
Basic OOP and C# interview questions. - Advanced Interview Questions
SOLID, DI, real-world scenario questions.