How can I downcast this object in java?

Question

public class Main {
    public static void main(String[] args) {
        Vehicle vehicle = new Vehicle();
        vehicle = (car) Vehicle;
    }
}

class Vehicle {
   static void transport() {

    }
}

class Car extends Vehicle {
    int age;
    String brand;
}

i understand that java implicitly upcasts, but I want to downcast this Vehicle instance and make it a Car. what am i doing wrong?

You can't downcast a reference into something that it isn't. — user207421, May 10 '22 at 00:11

score 1 · Accepted Answer · answered May 10 '22 at 00:06

Downcasting doesn't change what class the object is — it only changes what the compiler knows at compile-time. If you have a Vehicle which is not a Car (as you do, since you instantiated it as new Vehicle()), then you can't downcast it; any attempt to will result in a ClassCastException at runtime.

Other than that, what you're doing wrong is that you're downcasting using (car) instead of (Car). Java is case-sensitive.

How can I downcast this object in java?

1 Answers1