Number format?

[PinoyDev]

Good day!

I have a variable string that will hold numbers...I need a function that will check if the number meets the below criteria:

( Acceptable format )
-accept positive numbers
-accept negative numbers
-accept single decimal place (ex. 567.89)
-will not accept double demical place (ex. 567.89.678)
-will not accept single, double positive sign after a digit(ex. 98+45+)
-will not accept single, double negative sign after a digit(ex.34-, 98-45-)

<A little code demonstration>

Public Function Validate_Number(ByRef PassNumber as String) as Boolean
 'formatting conditions here
End Function

Private Sub TxtInputNumber_LostFocus()
If Validate_Number(TxtInputNumber.Text)=True Then
   msgbox "The Number is in Acceptable Format",vbInformation
else
   msgbox "The Number is Not an Acceptable Format",vbInformation
End Sub

I dont want to use masking as this is the required format to follow.

Thank you for helping!

[AndreRet]

If you google the following you should get plenty of sample code. You will be making use of the following functions to check for an integer value, search for characters etc -

IsNumeric
cInt
Mid
Left
Right
Replace
ASCii

With the above you can perform any validation check you need.

[RonalBertogi]

Here's mine for your number validation

Function Validate_Number(ByRef PassNumber As String) As Boolean
    Static szValidNum As String
    If szValidNum = "" Then _
        szValidNum = "0123456789"

    Dim szNum As String
    Dim c As String * 1, i As Integer, ch As Integer
    Dim dots As Integer, pluses As Integer, minuses As Integer
    ' Create a local copy of the PassNumber
    szNum = PassNumber
    ch = Len(szNum)
    ' Trim trailing dots.
    ' A number of multiple dots is number if these dots are the end of the number.
    ' We must be considerate
    Do While 1
        If Right(szNum, 1) <> "." Then Exit Do
        ch = ch - 1
        szNum = Left(szNum, ch)
    Loop
    For i = 1 To ch
        c = Mid(szNum, i, 1)
        If 0 = InStr(1, szValidNum, c) Then
            Select Case c
                Case "+"
                    'Make sure positive sign exists before anything else
                    If i > 1 Then Exit Function
                    'Make sure we are the only sign in this number
                    If minuses Then Exit Function
                    pluses = pluses + 1
                    'Reject multiple pluses
                    If pluses = 2 Then Exit Function
                Case "-"
                    'Make sure negative sign exists before anything else
                    If i > 1 Then Exit Function
                    'Make sure we are the only sign in this number
                    If pluses Then Exit Function
                    minuses = minuses + 1
                    'Reject multiple pluses
                    If minuses = 2 Then Exit Function
                Case "."
                    dots = dots + 1
                    'Make sure we are the only dot in this decimal number
                    If dots = 2 Then Exit Function
                Case Else
                    'Hell we are not a number!!!
                    Exit Function
            End Select
        End If
    Next i
    ValidateNum = True
End Function