Converting Java snippet to VBA

I have the following Java code:

Code:

---

public static void main(String [ ] args)
        {
                String isbn = "9781590387474";
                if (isbn.length() == 13 && isbn.indexOf("978") == 0)
                {
                  isbn = isbn.substring(3,12);
                  int xsum = 0;

                  for (int i = 0; i < 9; i++)
                  {
                      xsum += (10 - i) * Character.getNumericValue(isbn.charAt(i));
                  }

                  xsum %= 11;
                  xsum = 11 - xsum;

                  String x_val = String.valueOf(xsum);

                  switch (xsum)
                  {
                      case 10: x_val = "X"; break;
                      case 11: x_val = "0"; break;
                  }

                  isbn += x_val;
                }
                System.out.println(isbn);               
        }

---

I tried converting it to VBA myself, and got this:

Code:

---

Function UPCtoISBN(strUPCin As String) As String
    Dim strTemp As String
    If Len(strUPCin) = 13 And Left(strUPCin, 3) = "978" Then
       
        strTemp = Mid(strUPCin, 3, 10)
        Dim xsum As Integer
        xsum = 0
        For x = 1 To 9
            xsum = xsum + ((10 - x) * Mid(strTemp, x, 1))
        Next x
        xsum = xsum Mod 11
        xsum = 11 - xsum
        Select Case xsum
            Case 10
                strTemp = strTemp & "X"
            Case 11
                strTemp = strTemp & "0"
        End Select
       
    End If
    UPCtoISBN = strTemp
End Function

---

Unfortunately, it does not work.

Anyone willing to help fix it?

Thanks!

Well, I changed it to this:

Code:

---

Function UPCtoISBN(strUPCin As String) As String
    Dim strTemp As String
    If Len(strUPCin) = 13 And Left(strUPCin, 3) = "978" Then
       
        strTemp = Mid(strUPCin, 4, 9)
        Dim xsum As Integer
        xsum = 0
        For x = 1 To 9
            xsum = xsum + ((10 - x + 1) * Mid(strTemp, x, 1))
        Next x
        xsum = xsum Mod 11
        xsum = 11 - xsum
        Select Case xsum
            Case 10
                strTemp = strTemp & "X"
            Case 11
                strTemp = strTemp & "0"
            Case Else
                strTemp = strTemp & xsum
        End Select
       
    End If
    UPCtoISBN = strTemp
End Function

---

and it worked for all the books I checked.

Anyone care to try a few books of their own for me to validate?

Thanks!

It would be best to separate calculation of check digit, e.g. another package/class for check digit calculation.