Java question on car classes task (polymorphism)

Question

Hi, I think there is a bug in this assignment. Below is the full code I implemented which returns completely nothing. Even when I erase ElectricVehicle and HybridVehicle classes to just output vehicle.start() and .resource() which has been given in the assignment, nothing happens. Could you help me on this?

class Main {
public static void main(String[] args) {

Vehicle vehicle = new Vehicle();
Vehicle electric = new ElectricVehicle();
Vehicle hybrid = new HybridVehicle();

//calls
vehicle.start();
vehicle.resource();
electric.start();
electric.resource();
hybrid.start();
hybrid.resource();
}
}
class Vehicle{
public void start(){
System.out.println("Starting");
}
public void resource(){
System.out.println("I use petrol");
}
}

class ElectricVehicle extends Vehicle{
/*reimplement resource() method
to output "I use electricity"*/
public void resource(){
System.out.println("I use electricity");
}
}

}

class HybridVehicle extends Vehicle{
/*reimplement resource() method
to output "I use both petrol and electricity"*/
public void resource(){
System.out.println("I use petrol and electricity");
}
}

Answer 1

class Main {
public static void main(String[] args) {

Vehicle vehicle = new Vehicle();
Vehicle electric = new ElectricVehicle();
Vehicle hybrid = new HybridVehicle();

//calls
vehicle.start();
vehicle.resource();
electric.start();
electric.resource();
hybrid.start();
hybrid.resource();
}
}
class Vehicle{
public void start(){
System.out.println("Starting");
}
public void resource(){
System.out.println("I use petrol");
}
}

class ElectricVehicle extends Vehicle{
/*reimplement resource() method
to output "I use electricity"*/
public void resource(){
System.out.println("I use electricity");
}
}

class HybridVehicle extends Vehicle{
/*reimplement resource() method
to output "I use both petrol and electricity"*/
public void resource(){
System.out.println("I use both petrol and electricity");
}
}

Answer 2

There is a wrong curly brackett. The one above class HybridVehicle is too much.

https://code.sololearn.com/crmAjqs5n7RL/?ref=app

Answer 3

class Main {
public static void main(String[] args) {

Vehicle vehicle = new Vehicle();
Vehicle elVehicle = new elVehicle();
Vehicle hybrid = new hybridVehicle();

//calls
vehicle.start();
vehicle.resource();
elvehicle.start();
elvehicle.resource();
hybrid.start();
hybrid.resource();
}
}
class Vehicle{
public void start(){
System.out.println("Starting");
}
public void resource(){
System.out.println("I use petrol");
}
}

class elvehicle extends Vehicle{
/*reimplement resource() method
to output "I use electricity"*/
public void resource(){
System.out.println("I use electricity");
}
}

class hybridVehicle extends Vehicle{
/*reimplement resource() method
to output "I use both petrol and electricity"*/
public void resource(){
System.out.println("I use both petrol and electricity");
}
}

Answer 4

class Main {

public static void main(String[] args) {

Vehicle vehicle = new Vehicle();

Vehicle elVehicle = new elVehicle();

Vehicle hybrid = new hybridVehicle();

//calls

vehicle.start();

vehicle.resource();

elvehicle.start();

elvehicle.resource();

hybrid.start();

hybrid.resource();

}

}

class Vehicle{

public void start(){

System.out.println("Starting");

}

public void resource(){

System.out.println("I use petrol");

}

}

class elvehicle extends Vehicle{

/*reimplement resource() method

to output "I use electricity"*/

public void resource(){

System.out.println("I use electricity");

}

}

class hybridVehicle extends Vehicle{

/*reimplement resource() method

to output "I use both petrol and electricity"*/

public void resource(){

System.out.println("I use both petrol and electricity");

}

}
7th May 2022, 4:29 PM

Answer 5

Hi, thanks for replying. That wasn't it (not sure how it got here), since I would have just got a curly bracket error. It was a bug in the end, had to reload everything and it worked.

Answer 6

class Main {
public static void main(String[] args) {

Vehicle vehicle = new Vehicle();
Vehicle elVehicle = new elVehicle();
Vehicle hybrid = new hybridVehicle();

//calls
vehicle.start();
vehicle.resource();
elvehicle.start();
elvehicle.resource();
hybrid.start();
hybrid.resource();
}
}
class Vehicle{
public void start(){
System.out.println("Starting");
}
public void resource(){
System.out.println("I use petrol");
}
}

class elvehicle extends Vehicle{
/*reimplement resource() method
to output "I use electricity"*/
public void resource(){
System.out.println("I use electricity");
}
}

class hybridVehicle extends Vehicle{
/*reimplement resource() method
to output "I use both petrol and electricity"*/
public void resource(){
System.out.println("I use both petrol and electricity");
}
}

Answer 7

Can anyone tell me why I get no output?

class Main {
public static void main(String[] args) {

Vehicle vehicle = new Vehicle();
Vehicle electric = new ElectricVehicle();
Vehicle hybrid = new HybridVehicle();

//calls
vehicle.start();
vehicle.resource();
electric.start();
electric.resource();
hybrid.start();
hybrid.resource();
}
}
class Vehicle{
public void start(){
System.out.println("Starting");
}
public void resource(){
System.out.println("I use petrol");
}
}

class ElectricVehicle extends Vehicle{
/*reimplement resource() method
to output "I use electricity"*/
public void resource(){
System.out.println("I use electricity");
}

}

class HybridVehicle extends Vehicle{
/*reimplement resource() method
to output "I use both petrol and electricity"*/
public void resource(){
System.out.println("I use both petrol and electricity");
}

Answer 8

class main
{
public static void main(String args[])
{
System.out.println("Starting");
System.out.println("I use petrol");

System.out.println("Starting");

System.out.println("I use electricity");

System.out.println("Starting");
System.out.println("I use both petrol and electricity");

}
}