How do I find the Excel column name that corresponds to a given integer? [duplicate]

Answer 1

Ruby one-liner:

def column_name_for(some_int)
    some_int.to_s(26).split('').map {|c| (c.to_i(26) + 64).chr }.join # 703 => "AAA"
end

It converts the integer to base26 then splits it and does some math to convert each character from ascii. Finally joins 'em all back together. No division, modulus, or recursion.

Fun.

Answer 2

Considering the comment of wcm (top value = xfd), you can calculate it like this;

function IntToExcel(n: Integer); string;
begin
   Result := '';
   for i := 2 down to 0 do 
   begin
      if ((n div 26^i)) > 0) or (i = 0) then
         Result := Result + Char(Ord('A')+(n div (26^i)) - IIF(i>0;1;0));
      n := n mod (26^i);
   end;
end;

There are 26 characters in the alphabet and we have a number system just like hex or binary, just with an unusual character set (A..Z), representing positionally the powers of 26: (26^2)(26^1)(26^0).

Answer 3

I once wrote this function to perform that exact task:

public static string Column(int column)
{
    column--;
    if (column >= 0 && column < 26)
        return ((char)('A' + column)).ToString();
    else if (column > 25)
        return Column(column / 26) + Column(column % 26 + 1);
    else
        throw new Exception("Invalid Column #" + (column + 1).ToString());
}

Answer 4

This seems to work in vb.net

Public Function Column(ByVal pColumn As Integer) As String
    pColumn -= 1
    If pColumn >= 0 AndAlso pColumn < 26 Then
        Return ChrW(Asc("A"c) + pColumn).ToString
    ElseIf (pColumn > 25) Then
        Return Column(CInt(math.Floor(pColumn / 26))) + Column((pColumn Mod 26) + 1)
    Else
    stop
        Throw New ArgumentException("Invalid column #" + (pColumn + 1).ToString)
    End If
End Function

I took Joseph's and tested it to BH, then fed it 980-1000 and it looked good.

Answer 5

=CHAR(64+COLUMN())

Answer 6

In VBA, assuming lCol is the column number:

function ColNum2Letter(lCol as long) as string
    ColNum2Letter = Split(Cells(1, lCol).Address, "$")(0)
end function