This repository contains 10 comprehensive Object-Oriented Programming tasks that progress from basic concepts to advanced design patterns.

Note: These tasks were designed by Mustafa Elsherbiny and written with AI assistance.

These tasks can be completed in any OOP language: Java, C#, PHP, C++, Python, JavaScript/TypeScript, Ruby, or any other object-oriented programming language.

• Adapt the syntax and naming conventions to your chosen language
• Use equivalent data structures (Lists/Arrays, Maps/Dictionaries, etc.)
• Some advanced concepts like generics, events/delegates, or interfaces may have language-specific equivalents
• Code examples are provided in pseudocode or language-agnostic format

Focus: Basic classes, objects, methods, and collections

Learn the fundamentals of OOP by building a library system with books, members, and basic lending operations.

• ✅ Classes and objects
• ✅ Properties and methods
• ✅ Working with collections

👉 View Task 1

Practice working with collections and calculations by creating a gradebook system.

• ✅ Map/Dictionary collections
• ✅ Data processing and calculations
• ✅ String formatting

👉 View Task 2

Build a rental system that manages vehicles, customers, and rentals with date handling.

• ✅ Multiple interconnected classes
• ✅ Date/time operations
• ✅ Business logic implementation

👉 View Task 3

Create a restaurant ordering system with menu items, orders, and billing.

• ✅ Nested objects and collections
• ✅ Financial calculations
• ✅ State management

👉 View Task 4

Focus: Inheritance, polymorphism, interfaces, and enums

Implement a zoo system with abstract classes (or interfaces) and polymorphic animal behaviors.

• ✅ Abstract classes/interfaces
• ✅ Inheritance hierarchies
• ✅ Method overriding
• ✅ Polymorphism

👉 View Task 5

Build a hotel system with interfaces, enums, and complex date calculations.

• ✅ Interfaces
• ✅ Enums for type safety
• ✅ Composition relationships
• ✅ Business rules validation

👉 View Task 6

Create a banking system with inheritance and different account types.

• ✅ Inheritance
• ✅ Virtual and override methods
• ✅ Protected/private members
• ✅ Financial calculations

👉 View Task 7

Focus: Design patterns, generics, events/observers, queries, and SOLID principles

Develop a social platform with complex relationships and event-driven updates.

• ✅ Many-to-many relationships
• ✅ Event handling/observers
• ✅ Access control
• ✅ Chronological data management

👉 View Task 8

Build a supply chain system with generics, events/observers, and query operations.

• ✅ Generic classes
• ✅ Event handling/observers
• ✅ Query operations (filtering, sorting)
• ✅ Strategy pattern

👉 View Task 9

Create a comprehensive e-commerce system demonstrating all advanced OOP concepts.

• ✅ Multiple interfaces
• ✅ Design patterns (Strategy, Observer, Factory)
• ✅ SOLID principles
• ✅ Custom exceptions
• ✅ Advanced polymorphism

👉 View Task 10

1. Start with Level 1 if you're new to OOP
2. Progress sequentially through the tasks
3. Complete all bonus challenges for deeper learning
4. Review the learning goals before starting each task
5. Test your code thoroughly with the provided examples

Level 1 (Beginner) → Level 2 (Intermediate) → Level 3 (Advanced)
    Tasks 1-4            Tasks 5-7               Tasks 8-10

• Read the entire task before starting to code
• Plan your class structure before implementing
• Test incrementally as you build each class
• Use meaningful names for variables and methods
• Add comments to explain complex logic
• Complete the example usage to verify your implementation
• Try the bonus challenges to deepen your understanding

• Generics are called templates in C++, type parameters in other languages
• Events/Delegates can be implemented with observers, callbacks, or listeners
• Query operations (LINQ in C#, Streams in Java, array methods in JavaScript, etc.)
• Enums may be implemented as classes, constants, or native enum types depending on your language
• Interfaces may be called protocols, traits, or abstract base classes in some languages

Good luck on your OOP journey!