Object-Oriented Programming Interview Questions

public class Car {
    private String model;
    private int speed;
    private boolean engineStarted;
    
    // Default constructor (no parameters)
    public Car() {
        this.model = "Unknown";
        this.speed = 0;
        this.engineStarted = false;
        System.out.println("Car created with default constructor");
    }
    
    // Parameterized constructor
    public Car(String model) {
        this.model = model;
        this.speed = 0;
        this.engineStarted = false;
        System.out.println("Car created: " + model);
    }
    
    // Constructor with multiple parameters
    public Car(String model, int initialSpeed) {
        this.model = model;
        this.speed = initialSpeed;
        this.engineStarted = true;
        System.out.println("Car created: " + model + " at speed " + initialSpeed);
    }
    
    // Constructor overloading
    public Car(String model, String color) {
        this.model = model;
        this.speed = 0;
        this.engineStarted = false;
        System.out.println("Car created: " + color + " " + model);
    }
}

public class ConstructorDemo {
    public static void main(String[] args) {
        Car car1 = new Car();                    // Default constructor
        Car car2 = new Car("Toyota");           // One parameter
        Car car3 = new Car("Honda", 50);        // Two parameters
        Car car4 = new Car("BMW", "Red");      // Different parameters
    }
}