Reverse iteration through ArrayList gives IndexOutOfBoundsException

Question

When I reverse iterate over an ArrayList I am getting a IndexOutOfBoundsException. I tried doing forward iteration and there is no problem. I expect and know that there are five

Answer 1

Start the iteration at list.size() - 1 because array (or ArrayList) elements are numbered from 0 up through 1 less than the size of the list. This is a fairly standard idiom:

for (int j = list.size() - 1; j >= 0; j--) {
    // whatever
}

Note that your forward iteration works because it stops before reaching list.size().