Question about y_iterate

Hey all! I have one quick question. I want for example create iterator with 10 slots and it will hold player IDs.

If I got it right from y_less' examples on the official thread of foreach, default value of each slot in iterator is 0 right?

So how could I create an iterator with default values of i.e. -1 so I can store values inside that can begin with 0?

Thanks four your time. Cheers!