Introduction to Object-Oriented Programming (OOP) In Java

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Java is a fully object-oriented programming language, which means most of its structure revolves around the concept of objects and classes.

Instead of focusing only on actions or logic (like in procedural programming), Java organizes everything around real-world entities, such as a car, student, or bank account

each represented as an object with its own data (attributes) and behaviors (methods).

In simple terms, Object-Oriented Programming (OOP) allows you to build software the same way we see things in the real world, where every object has properties and actions.

Java’s Object-Oriented Programming is built on four core principles:

  1. Encapsulation
  2. Inheritance
  3. Polymorphism
  4. Abstraction

Key Concepts of Java OOP

In this example, we are learning the basic concept of classes and objects in Java, which are the building blocks of Object-Oriented Programming.

  • Class: A class is like a blueprint, for example, a “Car” blueprint that defines what every car has (brand, year) and what every car can do (display details).
  • Object: An object is like a real car built from that blueprint, for example, a Tesla made in 2023.

It means, each object can have its own values for brand and year but still follows the same class design.

Code example:

class Mobile {
    // Fields or properties
    String brand;
    int price;

    // Method or behavior
    void showDetails() {
        System.out.println("Mobile Brand: " + brand + ", Price: " + price);
    }
}

public class Main {
    public static void main(String[] args) {
        // Creating an object of Mobile class
        Mobile phone = new Mobile();
        phone.brand = "Samsung";
        phone.price = 25000;

        // Calling the method
        phone.showDetails();
    }
}

Output:

Mobile Brand: Samsung, Price: 25000

Here, you can learn the advanced concept about Classes and Objects in Java Programming…

Principles of Java OOP

1) Encapsulation

Encapsulation means keeping the data of a class safe by hiding it from direct access and allowing controlled interaction only through methods.

It’s like putting your valuables in a box and giving access through a lock, only the key holder (methods) can open it.

2) Inheritance

Inheritance allows one class to use the features of another class without rewriting the same code. It’s like a child automatically getting traits and habits from parents, but still able to develop their own path.

3) Polymorphism

Polymorphism allows the same action or method to behave differently depending on the object. It’s like the word “run”, it means different things for a program, a machine, or a person, but the idea remains similar.

4) Abstraction

Abstraction means focusing only on what an object does rather than how it does it. It hides unnecessary details and shows the essential information, just like you can drive a car without knowing how the engine works inside.

Benefits of OOP in Java

Object-oriented programming offers several practical benefits that make Java one of the most organized and reliable programming languages.

  1. Modularity: In OOP, the program is divided into small, independent classes. Each class has a specific purpose, so the code is easier to understand, manage, and debug.
  2. Reusability: OOP allows developers to reuse existing code instead of rewriting it. Through inheritance, a new class can use the properties and methods of an existing one, which saves time and reduces duplication in large projects.
  3. Flexibility: Polymorphism in Java provides flexibility by allowing different objects to respond differently to the same method call.
  4. Security: Encapsulation in OOP helps protect sensitive data by keeping it private within the class.

Common Applications of OOP

Here are some common areas where OOP plays a vital role:

  1. Game Development: Games are full of interactive elements like players, weapons, enemies, and environments. Each of these can be designed as objects with specific behaviors and properties.
  2. GUI Applications: In Graphical User Interface (GUI) programs, components like buttons, menus, text boxes, and windows are treated as objects. This object-based structure makes event handling and interface management more organized and efficient.
  3. Real-World Modelling: OOP helps developers to design software that mirrors real-world systems. For example, in banking software, customers, accounts, and transactions are represented by objects.

Also Learn Important Topics of Java

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