Enhancement of VBs Val function

Category:

Dates and Math

Type:

Snippets

Difficulty:

Beginning

Author:

Psycho

Version Compatibility:

More information:

This function, like VB's Val function, converts string values to long. It differs from VB's Val funciton in that it returns a default value (the function's second parameter) if it fails, whereas the VB version returns either 0, or a number for invalid input where the string begins with a number(e.g. ,Val(132wsdfas3423) returns 132).

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
' (None)

Code:

Public Function PsyVal(sdata As String, DefaultValue As Long) _
  As Long

'sData: = string data to convert
'DefaultValue = Number to return if conversion fails

'e.g., PsyVal("100", 150) = 100
'      PsyVal("100a", 150) = 150

Dim nSize As Long, nCount As Long
Dim multip As Integer
Dim nResult As Long, ntemp As Long

PsyVal = DefaultValue
    If Len(sdata) = 0 Then Exit Function
    nResult = 0
    nCount = 1
    If Mid(sdata, nCount, 1) = "-" Then
        multip = -1
        sdata = Right(sdata, Len(sdata) - 1)
    Else
        If Mid(sdata, nCount, 1) = "+" Then
            sdata = Right(sdata, Len(sdata) - 1)
        End If
        multip = 1
    End If
    nSize = Len(sdata)
    Do
        On Error GoTo MayOverFlow
        If IsNumeric(Mid(sdata, 1, 1)) Then
            If Mid(sdata, 1, 1) <> 0 Then
                ntemp = Val(Mid(sdata, 1, 1))
                While nSize > 1
                    ntemp = ntemp * 10
                    nSize = nSize - 1
                Wend
                nResult = nResult + ntemp
            End If
            sdata = Right(sdata, Len(sdata) - 1)
            nSize = Len(sdata)
        Else
            Exit Function
        End If
    Loop Until nSize = 0
    PsyVal = nResult * multip
    Exit Function

MayOverFlow:
    'donothing. Value already set

End Function