What's the efficiency of this program?

Question

What's the efficiency (in Big O notation) of a simple program that traverses a 2D array of ints and outputs each element.

Take the following code as an example:

public static void main(String args[])
{
   int[] array = {{1,2,3,4},
                  {5,6,7,8},
                  {9,10,11,12},
                  {13,14,15,16}};

    for(int i = 0; i < array.length; i++)
    {
       for(int j = 0; j < array[i].length; j++)
       {
          System.out.println(array[i][j]);
       }
    }
}

Answer 1

O (n*m) where n the number of arrays (first dimenstion) and m the max size of each internal array (second dimension)

Answer 2

I'd even note that the size of m is comparable to the size of n and make this O(n²).

Answer 3

Considering that your algorithm visits every element in the array once, it is O(n) where n is the size of the 2D array.