Object-Oriented Programming Principles in Java Explained

Object-oriented programming (OOP) is the paradigm upon which the entire Java language is built. Instead of writing linear code, you create objects that have their own properties and behaviors. This approach makes it much easier to work on large projects.
The four core principles of OOP are encapsulation, inheritance, polymorphism, and abstraction. Encapsulation allows you to hide a class’s internal implementation and provide access only through public methods. This protects data from misuse.
Inheritance makes it possible to create new classes based on existing ones. This helps avoid code duplication and build a class hierarchy. Polymorphism allows objects of different classes to respond differently to the same method. Abstraction helps highlight the essentials while hiding unnecessary details.
In Java, OOP is implemented using the keywords class, extends, implements, abstract, and interfaces. Proper use of these tools makes the code flexible and easy to maintain.
It is especially important to understand the difference between a class and an object. A class is a template, while an object is a specific instance of that template. Each object has its own state (fields) and behavior (methods).
A well-designed OOP architecture makes it easy to extend the program, add new functionality, and work in a team. That is why most companies require developers to have a deep understanding of these principles.