in c#, how can i build up array from A to ZZ that is similar to the way that excel orders columns

Question

i am looking for code that can generate an array where the first item is A, then B, then C . . .after Z i

Answer 1

To complement Vlad's answer, here's the reverse operation of ToBase26(int):

static long ToBase10(string str)
{
   if (string.IsNullOrWhiteSpace(str)) return 0;
   var value = str[0] - 'A' + 1;

   return (long) (value * Math.Pow(26, str.Length - 1) + 
          ToBase10(str.Substring(1, str.Length - 1)));
}