Java

// Main class name must match the filename (SampleProgram.java)
public class SampleProgram {

    // Main method: The entry point of any Java program
    public static void main(String[] args) {
        // Create an object of the Car class
        Car myCar = new Car("Toyota", 2023);

        // Call methods on the object
        myCar.displayDetails();
        myCar.startEngine();
    }
}

// A secondary class representing a real-world object
class Car {
    // Attributes (Variables)
    private String brand;
    private int year;

    // Constructor to initialize attributes
    public Car(String carBrand, int carYear) {
        this.brand = carBrand;
        this.year = carYear;
    }

    // Method to display car information
    public void displayDetails() {
        System.out.println("Car Brand: " + brand);
        System.out.println("Model Year: " + year);
    }

    // Method simulating an action
    public void startEngine() {
        System.out.println("The " + brand + "'s engine is now running.");
    }
}