Java Encapsulation and Rectangle Class Implementation

Understanding how to secure your code from unintended modifications is a critical step in becoming a professional software developer. This text-based course guides you through the foundational concepts of encapsulation in Java, using the practical example of a Rectangle class to bring these theories to life. You will start with the absolute basics of object-oriented design, defining key terminology and understanding why data hiding is essential for stable applications. From there, you will learn how to write clean, modern Java code that protects internal state while exposing a safe public interface. What you will learn: Understand the core principles of encapsulation and why data hiding matters; Create private fields and expose them safely using standard getter and setter methods; Write robust constructors to initialize objects with valid state; Apply modern Java features like records and basic validation logic; Implement custom methods to calculate area and perimeter within the class boundary. This course begins with essential definitions and step-by-step conceptual breakdowns before moving into structured code implementation and validation techniques. It is designed entirely for beginners with no prior object-oriented programming experience, though a basic familiarity with Java syntax is helpful. Start reading today to write safer, cleaner, and more maintainable Java code.