?? Day 1: Java Daily Insights - Understanding Object-Oriented Programming (OOP)

Today, let’s dive into one of the core concepts of Java: Object-Oriented Programming (OOP). OOP is fundamental to Java and allows developers to model real-world entities, making code more modular and reusable.

Key Principles of OOP

1. Encapsulation

Encapsulation is the concept of wrapping data (variables) and methods (functions) into a single unit called a class. This helps protect the data from outside interference and misuse.

- Example:

class Account {

private double balance; // Private variable

public void deposit(double amount) { // Public method

if (amount > 0) {

balance += amount; // Modify the balance

}

}

public double getBalance() { // Getter method

return balance; // Return the current balance

}

}

2. Inheritance

Inheritance allows one class (subclass) to inherit the properties and methods of another class (superclass). This promotes code reuse and establishes a hierarchical relationship between classes.

- Example:

class Vehicle {

void start() {

System.out.println("Vehicle is starting");

}

}

class Car extends Vehicle { // Car inherits from Vehicle

void honk() {

System.out.println("Car is honking");

}

}

3. Polymorphism

Polymorphism allows methods to do different things based on the object that it is acting upon, even if they share the same name. This can be achieved through method overloading and method overriding.

- Method Overloading: Same method name with different parameters.

- Method Overriding: Subclass provides a specific implementation of a method that is already defined in its superclass.

- Example:

class Animal {

void sound() {

System.out.println("Animal makes a sound");

}

}

class Dog extends Animal {

void sound() {

System.out.println("Dog barks"); // Overriding the sound method

}

}

4. Abstraction

Abstraction involves hiding the complex implementation details and showing only the essential features of the object. This can be achieved through abstract classes and interfaces.

- Example:

abstract class Shape { // Abstract class

abstract void draw(); // Abstract method

}

class Circle extends Shape {

void draw() {

System.out.println("Drawing a circle");

}

}

Key Takeaway

Understanding these OOP principles is essential for writing clean, maintainable, and reusable Java code. They form the backbone of many Java applications and frameworks.