[vb6] Convert formatted string into numeric

The function below is used to convert formatted string that produced by Format() function into numeric value (Double datatype). This function will remove all non-numeric string except minus and decimal delimiter.

Create new module and paste the source below inside your module file (.bas).

  '****************************************************************************
  ' Name        : StrToNumeric
  ' Author      : Chandra Gunawan
  ' Date        : 22-Jan-2009
  ' Description : Convert formatted string into numeric
  '****************************************************************************
  Public Function StrToNumeric( _
         ByVal pString As String, _
         Optional ByVal pDecimalDelimiter As String) As Double
         
    Dim I%, J%, strVal$
    
    If pDecimalDelimiter <> "." And pDecimalDelimiter <> "," Then
      pDecimalDelimiter = Trim(Format(0, "#.#"))
    End If
    
    'Remove all non-numeric except dot and comma
    For I = 1 To Len(pString)
      If InStr(1, "-0123456789" & pDecimalDelimiter, Mid(pString, I, 1)) > 0 Then
        strVal = strVal & Mid(pString, I, 1)
      End If
    Next
    
    'Remove unused delimiter
    J = Len(strVal) - Len(Replace(strVal, pDecimalDelimiter, ""))
    If J > 1 Then
      strVal = Replace(strVal, pDecimalDelimiter, "", 1, J - 1)
    End If
    
    'Replace to proper decimal delimiter
    If strVal = "" Or strVal = "." Then strVal = "0"
    StrToNumeric = CDbl(Replace(strVal, pDecimalDelimiter, "."))
  End Function  'StrToNumeric