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

Found this in SO albeit in PHP. Would this help? Algorithm to get the excel-like column name of a number

Answer 2

You can also try this. A to ZZ

public class Program
{
    public static void Main()
    {
        int c=1;
        string cc=AtoZZ(c);
        for(int i=1;i<=702;i++){
        cc=AtoZZ(i);
        Console.WriteLine(cc);
        }
    }

    static string AtoZZ(int chr)
    {
        char c1;
        char c2;
        string alp = "";
        if(chr<=26)
        {
            c1 = (char)(chr + 64);
            alp = c1 + "";
        }        
        else
        {
            int cl1 = chr / 26;
            int cl2 = chr % 26;
            if(cl2==0){
                cl1--;
                cl2=26;
            }
            c1 = (char)(cl1 + 64);
            c2 = (char)(cl2 + 64);
            alp = c1 + "" + c2;
        }
        return alp;
     }
}

Answer 3

var q = Enumerable.Range(Convert.ToInt32('A'),26).Select( x => Convert.ToChar(x) );
var result = (
  q.Select( x => x.ToString() )
   .Concat( 
      q.SelectMany(
        x => q.Select( y => x.ToString() + y.ToString() )
      )
   )
);

Answer 4

Great answer of Vlad.

Here's another variation on that:

 static IEnumerable<string> generate() {
   for (char c = 'A'; c <= 'Z'; c++) {
     yield return c.ToString();
   }

   foreach (string s in generate()) {
     for (char c = 'A'; c <= 'Z'; c++) {
       yield return s + c;
     }
   }
 }

If you don't mind starting the sequence with an empty string you could write it as follows:

 static IEnumerable<string> generate() {
   yield return "";

   foreach (string s in generate()) {
     for (char c = 'A'; c <= 'Z'; c++) {
       yield return s + c;
     }
   }
 }