Cloning a 2-D array

public class Main {
    public static void main(String[] args) {
        int[][] grid = {{1, 2}, {3, 4}};
        int[][] copy = grid.clone();
        copy[0][0] = 9;
        copy[1] = new int[] {7, 7};
        System.out.println(grid[0][0] + " " + grid[1][0]);
        System.out.println(copy[0][0] + " " + copy[1][0]);
    }
}