Java: fixed size array of 2D int array [duplicate]

Question

Is it possible to create an array of 2D int arrays like:

int n = 100;
int[][] [] a = new int[][] [n];

Array has a fixed length n and matrices (2D arrays) have different non-zero sizes (at least 1 x 1).

For performance I would like to store that in the stack, not like:

ArrayList<int[][]> a = new ArrayList<int[][]>(n);

which will be stored on the heap as far as I know.

Answer 1

To create a 3D array

int n = 100;
int[][][] a = new int[n][][];

This creates 100 array of array of any dimension.

This is almost as (in)efficient as

List<int[][]> a = new ArrayList<int[][]>(n);