Public Class Conversion

#Region "  Public Methods  "

    'Method to format phone numbers into a consistent pattern "(nnn) nnn-nnnn"
    'regardless of how passed in:
    '   First argument "phoneIn" specifies the phone number to format.
    '   Returns a string holding the formatted phone number.
    Public Shared Function PhoneNumber(ByVal phoneIn As String) As String

        Dim result As String = String.Empty

        'Remove illegal characters:
        Dim stripPattern As String = "[^0-9]"
        Dim stripRegex As Regex = New Regex(stripPattern)
        phoneIn = stripRegex.Replace(phoneIn, "")

        'Reverse the string ordering:
        phoneIn = ReverseString(phoneIn)

        'Construct the formatted phone number:
        For i As Integer = 1 To phoneIn.Length

            If i < 5 Then
                result = Mid(phoneIn, i, 1) & result
            End If

            If i = 5 Then result = "-" & result

            If 4 < i And i < 8 Then
                result = Mid(phoneIn, i, 1) & result
            End If

            If i = 8 Then result = ") " & result

            If 7 < i And i < 11 Then
                result = Mid(phoneIn, i, 1) & result
            End If

            If i > 8 And i = phoneIn.Length Then result = "(" & result

        Next i

        'Pass the result back to the caller:
        Return result

    End Function

#End Region

#Region "  Private Methods  "

    'Method to reverse the character order of a specified string:
    '   First argument "textIn" specifies the string to reverse.
    '   Returns a string in reverse order.
    Private Shared Function ReverseString(ByVal textIn As String) As String

        Dim currentCharacter As Char
        Dim result As String = String.Empty

        For counter As Long = textIn.Length To 1 Step -1
            currentCharacter = Mid(textIn, counter, 1)
            result = result & currentCharacter
        Next

        Return result

    End Function

#End Region


End Class