For some reason, the last line doesn't work at all. I've looked through different forums and kept finding the same code for adding the integers in an array, but nothing happens.

Code:
    public static void main(String[] args)
    {
        int[][] array2D = {{0,1,2,3},{4,5,6,7},{8,9,10,11},{12,13,14,15}};
        
        for (int row=0; row<array2D.length; row++)
        {
            for (int col=0; col<array2D[row].length+1; col++)
            {    
                if (col<array2D[row].length)
                {
                    System.out.print(array2D[row][col] + "\t");
                }
                else
                    System.out.println();
            }
        }
        int sum = 0;
        for (int i=0; i<array2D.length; i++){
            sum += array2D[i]; //this one has the error
        }
        System.out.println ("The sum of all the elements is: " + sum);
I've just started learning Java this month, so I really need the help. Thanks!