Questions about ArrayList

Questions about ArrayList

I need to use an ArrayList, but I am not sure how o do some these things
that would be possible with a normal array.
1) This:
int[][] example1 = new int[10][20];
(an array with two arguments (10, 20)) is possible with normal arrays, but
how to do it with an ArrayList.
2) How to increase the value of an int on the list by 1, like this:
example2[3][4] ++;