Most C# developers understand that there’s a difference between a “rectangular” and a “ragged” two-dimensional array.

int[,] rectangle = { 
  {10, 20}, 
  {30, 40}, 
  {50, 60} }; 
int[][] ragged = { 
  new[] {10},
  new[] {20, 30},
  new[] {40, 50, 60} };

Here we have a two-dimensional array with six elements, arranged in three rows of two elements each. And we have a one-dimensional array with three elements, where each element is itself a one-dimensional array with one, two or three elements.

That’s all very straightforward. Where things get brain-destroying is when you try to make a ragged array of two-dimensional arrays.  Continue reading →