Question

I have an old function I can’t change who want an int[][] for parameter is there a way to map
ArrayList<ArrayList<Integer>> to int[][]

Answer 1

Get the size of the ArrayLists into i and j ,respectively
Increment i and j according to your logic

int i = 0;
for(ArrayList<Integer> a1 : outer){
    int j=0;
    for(Integer k : a1){
       yourarray[i][j++] = k;
    }
    i++;
}