title: Adding the diagonal values in a 2d array
body: <p>I have the following 2d array</p>
  
  <pre><code>        int [][] array = {{ 0,  1,  2,  3,  4,  5,  6,  7,  8,  9},
                            {10, 11, 12, 13, 14, 15, 16, 17, 18, 19},
                            {20, 21, 22, 23, 24, 25, 26, 27, 28, 29},
                            {30, 31, 32, 33, 34, 35, 36, 37, 38, 39},
                            {40, 41, 42, 43, 44, 45, 46, 47, 48, 49},
                            {50, 51, 52, 53, 54, 55, 56, 57, 58, 59},
                            {60, 61, 62, 63, 64, 65, 66, 67, 68, 69},
                            {70, 71, 72, 73, 74, 75, 76, 77, 78, 79},
                            {80, 81, 82, 83, 84, 85, 86, 87, 88, 89},
                            {90, 91, 92, 93, 94, 95, 96, 97, 98, 99}};
  </code></pre>
  
  <p>I have this code to find the sum of all the values in the array. How can I modify it to add only the diagonal values starting at 0 (0+11+22+33 etc.)?</p>
  
  <pre><code> public static int arraySum(int[][] array)
  {
      int total = 0;
  
      for (int row = 0; row &lt; array.length; row++)
      {
          for (int col = 0; col &lt; array[row].length; col++)
              total += array[row][col];
      }
  
      return total;
  }
  </code></pre>