How to convert a column number (e.g. 127) into an Excel column (e.g. AA)

Question

How do you convert a numerical number to an Excel column name in C# without using automation getting the value directly from Excel.

Excel 2007 has a possible range o

Answer 1

..And converted to php:

function GetExcelColumnName($columnNumber) {
    $columnName = '';
    while ($columnNumber > 0) {
        $modulo = ($columnNumber - 1) % 26;
        $columnName = chr(65 + $modulo) . $columnName;
        $columnNumber = (int)(($columnNumber - $modulo) / 26);
    }
    return $columnName;
}

Answer 2

If anyone needs to do this in Excel without VBA, here is a way:

=SUBSTITUTE(ADDRESS(1;colNum;4);"1";"")

where colNum is the column number

And in VBA:

Function GetColumnName(colNum As Integer) As String
    Dim d As Integer
    Dim m As Integer
    Dim name As String
    d = colNum
    name = ""
    Do While (d > 0)
        m = (d - 1) Mod 26
        name = Chr(65 + m) + name
        d = Int((d - m) / 26)
    Loop
    GetColumnName = name
End Function

Answer 3

private String getColumn(int c) {
    String s = "";
    do {
        s = (char)('A' + (c % 26)) + s;
        c /= 26;
    } while (c-- > 0);
    return s;
}

Its not exactly base 26, there is no 0 in the system. If there was, 'Z' would be followed by 'BA' not by 'AA'.

Answer 4

Another VBA way

Public Function GetColumnName(TargetCell As Range) As String
    GetColumnName = Split(CStr(TargetCell.Cells(1, 1).Address), "$")(1)
End Function

Answer 5

Coincise and elegant Ruby version:

def col_name(col_idx)
    name = ""
    while col_idx>0
        mod     = (col_idx-1)%26
        name    = (65+mod).chr + name
        col_idx = ((col_idx-mod)/26).to_i
    end
    name
end

Answer 6

Easy with recursion.

public static string GetStandardExcelColumnName(int columnNumberOneBased)
{
  int baseValue = Convert.ToInt32('A');
  int columnNumberZeroBased = columnNumberOneBased - 1;

  string ret = "";

  if (columnNumberOneBased > 26)
  {
    ret = GetStandardExcelColumnName(columnNumberZeroBased / 26) ;
  }

  return ret + Convert.ToChar(baseValue + (columnNumberZeroBased % 26) );
}