In Java it's just as follows. I don't know if there is a .length method/function in C# though!

Code:
int[][] arrayName = new int[2][2];
Then you could just tranverse the array with a nested loop to either look up a value or fill the array.

Code:
(for int i=0; i < arrayName.length; i++)
 {
  for(int j = 0; j < arrayName[i].length; j++)
    {
     //do whatever
    }
   // do whatever
  }