I am trying to increment an integer based on a click. How the click happens does not matter so I'll stick to the logic. I am doing this in Java but the logic should be the same all around.

```
int index = 0;

// then within the click event
//arrySize holds the size() of an ArrayList which is 10

index = (index + 1) % arrySize;

```

With this logic, every time the user clicks, `index` will increment by 1. Then its modulo of `arrySize` causes `index` to go back to 0 when `index` matches `arrySize` 

*(10 % 10 would make the index go back to 0)* Which is great because it's kind of like a loop that goes from 0 to 10 then back to 0 and never over 10.

I am trying to do the same logic but **backwards**
where based on the click the number will decrement and get to 0 then
goes back to the `arrySize` instead of `-1`

How can I achieve this logic?