CODEWITHSUNDEEP
excelfunctioncharacter
kevindstanley
kevindstanley

Reputation: 282

How to get Column Number(or index) from Excel Column Letter

I have searched through this site and googled for a formula. I need to calculate an Excel column number FROM the letter such as: 

A=1
B=2
..
AA=27
AZ=52
...
AAA=703

The code seems to be 1 digit off after random cycles of the alphabet(AZ -> BA == off digit). It also will seemingly randomly produce the same integer from two different inputs: 

GetColumnNumber(xlLetter : Text) : Integer //Start of function

 StringLength := STRLEN(xlLetter);
 FOR i := 1 TO StringLength DO BEGIN
 Letter := xlLetter[i];
   IF i>1 THEN
     Count += ((xlLetter[i-1]-64) * (i-1) * 26) - 1;
   Count += (Letter - 64);
 END;
 EXIT(Count); //return value

My code example is written in C/AL which is used for Dynamics NAV, but I can write C# or vb.net as well so I wouldn't mind if an example was in either of those languages.

Upvotes: 3

Views: 5761

Answers (3)

Oops4Me
Oops4Me

Reputation: 1

In VBA: (Recursive Function)

    Function Get_Col_Number(strColName As String, dRunningNo As Integer) As Double
        Dim dCurrentColNo As Double
        Dim dMultipleValue As Double

        strColName = Ucase(strColName)

        If (dRunningNo <= 0) Then Get_Col_Number = 0:   Exit Function

        dCurrentColNo = ((Asc(Mid(strColName, dRunningNo, 1)) - Asc("A") + 1))
        dMultipleValue = 26 ^ (Len(strColName) - dRunningNo)

        Get_Col_Number = (dCurrentColNo * dMultipleValue) + Get_Col_Number(strColName, (dRunningNo - 1))
    End Function

Use this Function as below.

Sub Main()
    Dim StrGetNoForThisColumnName As String
    StrGetNoForThisColumnName = "Xfd"

    Msgbox "Final Result : " & Get_Col_Number(StrGetNoForThisColumnName, Len(StrGetNoForThisColumnName))
End Sub

Upvotes: 0

stenci
stenci

Reputation: 8501

In VBA:

Function ColLetter(C As Integer) As String
  If C < 27 Then
    ColLetter = Chr(64 + C)
  Else
    ColLetter = ColLetter((C - 1) \ 26) & ColLetter((C - 1) Mod 26 + 1)
  End If
End Function

Upvotes: 3

Tim Williams
Tim Williams

Reputation: 166980

In VBA:

Public Function GetCol(c As String) As Long
    Dim i As Long, t As Long
    c = UCase(c)
    For i = Len(c) To 1 Step -1
        t = t + ((Asc(Mid(c, i, 1)) - 64) * (26 ^ (Len(c) - i)))
    Next i
    GetCol = t
End Function

Upvotes: 3

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