Finding duplicate values in arraylist

Question

I have an ArrayList

For Example

class Car{
   String carName;
   int carType;
}

Now, I have to find if the

Answer 1

If you have

class Car{
   String carName;
   int carType;
}

and

List list;

that contains a list of cars, then you could have a method like

public static boolean hasDuplicates(List p_cars) {
    final List usedNames = new ArrayList();
    for (Car car : p_cars) {
        final String name = car.carName;

        if (usedNames.contains(name)) {
            return true;
        }

        usedNames.add(name);
    }

    return false;
}

to find out whether the list of cars have cars with duplicate names.