Given the following code:

abstract class Vehicle {

    abstract void start();

}

class Car extends Vehicle {

    void start() {

        System.out.println("Car starting...");

    }

}

What is the significance of the abstract keyword in the Vehicle class?

Which object in JDBC is used to execute an SQL query?

What is the primary role of the Model in JavaFX MVC?

In a java class, we must write at least one constructor.

Given the following code:

interface Printer {

    void print();

}

class LaserPrinter implements Printer {

    public void print() {

        System.out.println("Laser");

    }

    public void warmUp() {

        System.out.println("Warming up...");

    }

}

public class Test {

    public static void main(String[] args) {

        Printer p = new LaserPrinter();

        p.print();

        p.warmUp();

    }

}

What happened?

When a static variable is modified in one instance of a class, how does it affect other instances?

In JavaFX, The View should know about the internal implementation details of the Model.

How can you add an element to an ArrayList in Java?