Question

How do I initialize the values of an ArrayList?

I found this on the internet, but it doesn’t work.

ArrayList<Kaart>[] hand = (ArrayList<Kaart>[]) new ArrayList[AANTALSPELERS];

All elements of hand are null. I get a nullPointerException because of that. Kaart is a class I created. AANTALSPELERS is a private static final int.

Answer 1

This is the correct way, using generics. Notice that the warning is unavoidable (you can use a @SuppressWarnings annotation if that’s a problem):

ArrayList<Kaart>[] array = (ArrayList<Kaart>[]) new ArrayList[AANTALSPELERS];
for (int i = 0; i < AANTALSPELERS; i++)
    array[i] = new ArrayList<Kaart>();