C# Object-Oriented Programming Handbook

A structured C# OOP learning repository from fundamentals to advanced object-oriented design.

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About

This repository is a chapter-by-chapter guide to Object-Oriented Programming in modern C#. This page is a navigation hub only. Every lesson, diagram, interview question and exercise lives inside its own chapter folder.

Each chapter includes: concepts · syntax · examples · diagrams · common mistakes · best practices · interview questions · practice problems.

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⚡ Quick Navigation

Foundations

• Core OOP
• Type Design
• Object Model
• SOLID

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🎚️ Level System

Level	Chapters
🟢 Beginner	01–07
🟡 Core OOP	08–12
🟠 Intermediate	13–18
🔵 Advanced	19–23
🔴 Design Principles	24

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📚 OOP Learning Path

🟢 Module 01 — OOP Foundations

Chapter	Topic	Link
01	Introduction to OOP	Read →
02	Classes	Read →
03	Objects	Read →
04	Fields	Read →
05	Properties	Read →
06	Methods	Read →
07	Constructors	Read →

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🟡 Module 02 — Core OOP Principles

Chapter	Topic	Link
08	Encapsulation	Read →
09	Inheritance	Read →
10	Polymorphism	Read →
11	Abstraction	Read →
12	Interfaces	Read →

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🟠 Module 03 — OOP Type Design

Chapter	Topic	Link
13	Static Members	Read →
14	Sealed Members	Read →
15	Abstract Class vs Interface	Read →
16	Access Modifiers	Read →
17	this Keyword	Read →
18	base Keyword	Read →

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🔵 Module 04 — .NET Object Model

Chapter	Topic	Link
19	System.Object	Read →
20	Boxing & Unboxing	Read →
21	Type Casting	Read →
22	Record vs Class	Read →
23	Garbage Collection	Read →

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🔴 Module 05 — Object-Oriented Design

Chapter	Topic	Link
24	SOLID Principles	Read →

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📖 Recommended Study Order

1. Follow the chapters in numeric order. Each one builds on the previous.
2. Read the chapter, then run its project in examples/.
3. Attempt the chapter's problems in exercises/ before checking solutions/.
4. Revisit the Interview Questions section of each chapter before interviews.

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🗂️ Repository Structure

csharp-oop-handbook/
│
├── README.md
├── 01-oop-introduction/
├── 02-classes/
├── 03-objects/
├── ...
├── 24-solid-principles/
│
├── diagrams/
├── examples/
├── exercises/
└── solutions/

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🤝 Contributing

Contributions are welcome: fixes, clearer explanations, better examples and new exercises. Please read CONTRIBUTING.md first and keep every chapter on the standard template.

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📄 License

Released under the MIT License.

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Start here → 📘 Chapter 01: Introduction to OOP