java ArrayList contains different objects

Answer 1

Yes you can. But you need a common class to your object types. In your case this would be Vehicle.

So for instance:

Vehicle class:

public abstract class Vehicle {
    protected String name;
}

Bus class:

public class Bus extends Vehicle {
    public Bus(String name) {
        this.name=name;
    }
}

Car class:

public class Car extends Vehicle {
    public Car(String name) {
        this.name=name;
    }
}

Main class:

public class Main {
    public static void main(String[] args) {
        Car car = new Car("BMW");
        Bus bus = new Bus("MAN");
        ArrayList list = new ArrayList();
        list.add(car);
        list.add(bus);
   }
}