Object-Oriented Programming in Kotlin

This repository contains practical examples and supporting code for learning object-oriented programming (OOP) using Kotlin. It is part of the course Diseño e Implementación de Bibliotecas de Software (DIBS) — Design and Implementation of Software Libraries — offered in Spanish.

🧑‍🏫 Although the course is taught in Spanish, all the code (including comments and documentation) is written in English to make it more accessible to a broader audience.

✅ The examples prioritize clarity, safe design, and idiomatic Kotlin practices.

📚 Current Lesson: Open and Closed Classes

The first module focuses on open and closed classes, a foundational topic for designing safe and extensible APIs.

In Kotlin, classes and methods are closed by default — they cannot be inherited or overridden unless explicitly marked with the open modifier. This lesson shows how this default behavior protects your code from the fragile base class problem and aligns with the Open/Closed Principle.

🗂️ Module structure

open-closed/
└── src/main/kotlin/cl/ravenhill/
    └── database/
        ├── DatabaseConnection.kt
        └── EncryptedDatabaseConnection.kt

Files

• DatabaseConnection.kt: A base class with selective use of open to control inheritance.
• EncryptedDatabaseConnection.kt: A subclass that safely overrides a specific method.

🔗 Lesson Link

Read the full lesson here:
👉 Open and Closed Classes for Inheritance

🧠 Goals

This project is intended to help you:

• Understand OOP concepts from a Kotlin perspective.
• Write safer, more maintainable object-oriented code.
• Design library APIs that are robust and extensible.