Syntax

The declaration and use of a multidimensional array is very similar to that of a single dimension array.

int[][] grid = new int[N][M];
int[][][] cube = new int[X][Y][Z];

grid[0][1] = cube[0][0][0];
grid[0].length; // M
cube[0].length; // Y

As more dimensions are added, the memory required grows exponentially.

Complexity

Time complexity

Access: $\mathcal{O}(1)$

Space complexity

$\mathcal{O}(S_0 \times S_1 \times S_2 \times \dots \times S_k)$, where $S_i$ is the size of the $i^\text{th}$ dimension.