Comments on: An Array of Column Letters

By: keepITcool

keepITcool — Thu, 20 Jan 2005 14:16:00 +0000

More ColumnLetter functions..
shorter and 2x faster than Gary's overcomplex code. >10x faster than Rob's elegant one-line solution

Function ColumnLetter(ByVal colNum As Long) As String
colNum = (colNum - 1) Mod 256
If colNum > 25 Then ColumnLetter = Chr$(64 + colNum 26)
ColumnLetter = ColumnLetter & Chr$(65 + colNum Mod 26)
End Function

It does have a drawback if Excel ever gets beyond the 256 column boundary.. Following s/b future proof.

Function ColumnLetter(ByVal colNum As Long) As String
Do
ColumnLetter = Chr$(65 + (colNum - 1) Mod 26) & ColumnLetter
colNum = (colNum - 1) 26
Loop While colNum > 0
End Function

By: Jon Peltier

Jon Peltier — Tue, 18 Jan 2005 13:54:00 +0000

Like Dennis, I've always cycled through the areas when I have a discontiguous range. I had to test this to be sure it worked.

Rob's column number to letter code is pretty cool, too.

By: Dennis

Dennis — Tue, 18 Jan 2005 11:10:00 +0000

That's fantastic. Thanks everyone. My version had me monkeying around with Areasquite unnecessarily as it turns out!

(Thanks also to RobI saw your ColumnLetter function on your website a while ago, and started using it because it's about 15 lines shorter than my own stab at this!)

By: Dick

Dick — Mon, 17 Jan 2005 23:39:00 +0000

Not a typo, just WordPress assuming it knows how to code HMTL. The syntax hiliter is the best code rendering I’ve seen, but it still sucks. Any code with an ampersand or integer division is at risk. I’ll see if I can figure out how to escape it.

By: Gary Waters

Gary Waters — Mon, 17 Jan 2005 22:09:00 +0000

Dick,

Thanks for including my code. I did discover later on that you can eliminate the 'if colNum > x Then' statement because of the 'i' variables initialization.

By: Jake Marx

Jake Marx — Mon, 17 Jan 2005 22:05:00 +0000

Dick,

Just another way of doing it. Seems to execute in about the same time.

Private Const msRANGE As String = "C:D,F:I,L:Q"

Sub Demo()
Dim rngCol As Range
Dim sTemp As String
Dim asNewAddr() As String
Dim lIdx As Long

For Each rngCol In Range(msRANGE).Columns
ReDim Preserve asNewAddr(lIdx)
sTemp = rngCol.Address(False, False)
asNewAddr(lIdx) = Left$(sTemp, _
InStr(1, sTemp, ":", _
vbBinaryCompare) - 1)
lIdx = lIdx + 1
Next rngCol
End Sub

By: Rob van Gelder

Rob van Gelder — Mon, 17 Jan 2005 21:31:00 +0000

Hi Dick,

Typo:
In the function ColumnLetter with the line starting with Chr there is a missing backslash - just before the number 26 should go a backslash (integer divide)

Out of interest, the ColumnLetter function I use is
Split(Columns(colNum).Address(, False), ":")(1)

Cheers,
Rob