VBA function to find number of decimal places

[chirp]

Hey,

I need a function to find the number of decimal places of a certain number (in this specific case doubles)

The first solution would be something like this:

'returns the number of decimal places within a double
Public Function getDecPlaces(inputNum As Double) As Long
Dim ndx As Long
ndx = InStr(1, inputNum, ".")
If ndx > 0 Then
    getDecPlaces = Len$(CStr(inputNum)) - ndx
End If
End Function

But i feel there is likely a much better way of doing this...any help would be appreciated!!

 

[chirp]

rick..most likely!

mike...Thanks that is very cool and fast! i will use that approach in my function!

 

[chirp]

another solution would be to use the strReverse function which, with the short ~15 length strings is relatively fast...this results in a simple and fast method as in:

'Returns number of decimal places from a double
Public Function getDecPlaces(tDub As Double) As Long
    getDecPlaces = InStr(1, StrReverse(CStr(tDub)), ".")
    getDecPlaces = getDecPlaces - Abs(CLng(getDecPlaces <> 0))
End Function

 

[Rick Rothstein]

I don't know for sure, but I think this UDF should be quite fast...

Function AfterPoint(S As String) As Long
  Dim X As Byte, B() As Byte
  B = S
  For X = 1 To UBound(B)
    If B(X) = 46 Then
      AfterPoint = Len(S) - 1 - X / 2
      Exit Function
    End If
  Next
End Function

 

[chirp]

i think that the byte array method is good, but just copying the input into the byte array takes roughly the same time as the other methods (on my computer). in general i find working with byte arrays usually is faster but not necessarily for such small strings