In one class I have constructor which looks like:
Class(int x, int y, int[] moves);
In other class which creates those objects I have moves stored in ArrayList. Moves are numbers. So when this class decides ti create new object it must first convert this ArrayList into array. So I tried something like this:
new Object(0, 0, (int[])moves.toArray(int[moves.size()]);
But it doesn't work. How should it be done properly?
The result of calling toArray() on an ArrayList is never an int[]. You can't have an ArrayList<int> in Java due to the way generics works. At best it would be an Integer[], which you'd then need to convert. Note that even though you can convert from Integer to int, you can't cast an Integer[] to an int[]. Something has to loop over the values.
You could just do it directly:
int[] values = new int[moves.size()];
for (int i = 0; i < values.length; i++) {
values[i] = moves.get(i);
}
Alternatively could create an Integer[] and then convert from that - but why do the copying twice?
moves.toArray(new Integer[moves.size()] would suffice .
Integer[], does it? Something's going to loop... given that you don't have the right types, it might as well be your code.