Translate a column index into an Excel Column Name

Question

Given a columns\' index, how can you get an Excel column name?

The problem is trickier than it sounds because it\'s not just base-26. The columns

Answer 1

this is with Swift 4 :

@IBAction func printlaction(_ sender: Any) {
    let textN : Int = Int (number_textfield.text!)!
    reslut.text = String (printEXCL_Letter(index: textN))
}


func printEXCL_Letter(index : Int) -> String {

    let letters = ["a", "b", "c","d", "e", "f","g", "h", "i","j", "k", "l","m", "n", "o","p", "q", "r","s", "t", "u","v","w" ,"x", "y","z"]

    var index = index;
    index -= 1
    let index_div = index / 26

    if (index_div > 0){
        return printEXCL_Letter(index: index_div) + letters[index % 26];
    }
    else {
        return letters[index % 26]
    }
}

Answer 2

It's for this very reason that I avoid column names in programmed interface to Excel. Using column numbers works very well in Cell(r,c) references and R1C1 addressing.

EDIT: The Range function also takes cell references, as in Range(Cell(r1,c1),Cell(r2,c2)). Also, you can use the Address function to get the A1-style address of a cell or range.

EDIT2: Here's a VBA function that uses the Address() function to retrieve the column name:

Function colname(colindex)
    x = Cells(1, colindex).Address(False, False) ' get the range name (e.g. AB1)
    colname = Mid(x, 1, Len(x) - 1)              ' return all but last character
End Function

Answer 3

This is an old post, but after seeing some of the solutions I came up with my own C# variation. 0-Based, without recursion:

public static String GetExcelColumnName(int columnIndex)
{
    if (columnIndex < 0)
    {
        throw new ArgumentOutOfRangeException("columnIndex: " + columnIndex);
    }
    Stack<char> stack = new Stack<char>();
    while (columnIndex >= 0)
    {
        stack.Push((char)('A' + (columnIndex % 26)));
        columnIndex = (columnIndex / 26) - 1;
    }
    return new String(stack.ToArray());
}

Here are some test results at key transition points:

0: A
1: B
2: C
...
24: Y
25: Z
26: AA
27: AB
...
50: AY
51: AZ
52: BA
53: BB
...
700: ZY
701: ZZ
702: AAA
703: AAB

Answer 4

In Ruby:

class Fixnum
  def col_name
    quot = self/26
    (quot>0 ? (quot-1).col_name : "") + (self%26+65).chr
  end
end

puts 0.col_name # => "A"
puts 51.col_name # => "AZ"

Answer 5

Here's Joel's awesome code modified to work with zero-based column indexes and without the char array.

 Public Shared Function GetExcelColumn(ByVal index As Integer) As String

        Dim quotient As Integer = index \ 26 ''//Truncate 
        If quotient > 0 Then
            Return GetExcelColumn(quotient - 1) & Chr((index Mod 26) + 64).ToString

        Else
            Return Chr(index + 64).ToString

        End If

    End Function

Answer 6

JavaScript Solution

/**
 * Calculate the column letter abbreviation from a 0 based index
 * @param {Number} value
 * @returns {string}
 */
getColumnFromIndex = function (value) {
    var base = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');
    value++;
    var remainder, result = "";
    do {
        remainder = value % 26;
        result = base[(remainder || 26) - 1] + result;
         value = Math.floor(value / 26);
    } while (value > 0);
    return result;
};