Mobile App development - 🎓 Lecture 24: OOP Concepts in Java | Association, Composition & Aggregation Explained with Examples

Welcome to Lecture 24 of the Java Programming Series on the Edlify YouTube Channel, presented by Bilal Arif, Lecturer at the School of Systems and Technology (SST), University of Management and Technology (UMT) Lahore. In this lecture, we explore one of the most important aspects of Object-Oriented Programming (OOP) — the relationships between classes. Understanding how classes relate and interact with each other is key to designing flexible, reusable, and efficient software. This session focuses on Association, Composition, and Aggregation in Java, explained in a clear, structured, and practical way — with real-world coding examples that help you build a solid understanding of how Java manages object relationships. 🧠 What You Will Learn in This Lecture By the end of this lecture, you’ll understand: What Association, Aggregation, and Composition mean in Object-Oriented Programming. How these relationships are represented and implemented in Java. The difference between weak and strong relationships between objects. How to identify which type of relationship to use in your program design. Real-world examples and UML concepts illustrating these relationships. This lecture builds on your previous understanding of Classes, Objects, and Encapsulation, moving toward advanced OOP relationships that help create structured and maintainable software systems.