Introduction to Object-Oriented Programming (OOP)

Object-Oriented Programming (OOP) is a way of organizing code around objects. These objects combine data (called attributes) and behavior (called methods) that operate on the data.

Why Use OOP?

OOP offers several advantages:

• Modularity: Breaks programs into smaller, manageable parts (classes and objects).
• Reusability: Makes it easier to reuse existing code in new programs.
• Maintainability: Simplifies fixing bugs and making updates.
• Scalability: Allows for easy addition of new features.

Core Concepts of OOP

1. Class: A blueprint or template for creating objects.
2. Object: An instance of a class.
3. Attributes: The properties or characteristics of an object (e.g., brand, speed).
4. Methods: The actions or behaviors of an object (e.g., start(), accelerate()).

Example: Car Class

Defining the Class

class Car {
    // Attributes
    String brand;
    int speed;
 
    // Methods
    void start() {
        System.out.println(brand + " is starting.");
    }
 
    void accelerate(int increment) { // Method
        speed += increment;
        System.out.println("New speed: " + speed);
    }
}

Attributes

Attributes define the properties of an object:

String brand;
int speed;

Methods

Methods define the behavior of an object:

void start() {
    System.out.println(brand + " is starting.");
}
 
void accelerate(int increment) {
    speed += increment;
    System.out.println("New speed: " + speed);
}

Creating Objects

An object is an instance of a class. To create an object, we use the new keyword followed by a call to a constructor of the class.

Car car1 = new Car(); // Object creation
car1.start();         // Using an object to call a method

This creates a new Car object with the specified brand, model, and year.

Accessing Object Members

We can access the fields and methods of an object using the dot notation:

System.out.println(myCar.brand);  // Outputs: Toyota
myCar.startEngine();  // Outputs: The Toyota Corolla is starting...