I had to come up with a quick routine and tossed it off in VB. The guy working on the project is a C# dude. I used the reflector to get c# code for him and noticed some very bad things in the output. Is this an issue with the disassembly output by Reflector or is this goofyness winding up in production?
The original:
Public Function CalculateCheckDigitVB(ByVal Input As String) As String
Dim _temp As String = Input.Trim.ToUpper
Dim _digitTest As String = String.Empty
Dim _sum As Integer = 0
Dim _weight As Integer = 0
Dim _digit As Integer = 0
If _temp = String.Empty Then
Return String.Empty
End If
_temp = _temp.PadLeft(17, "0"c)
For _index As Integer = 0 To 16
_digitTest = _temp.Substring(_index, 1)
Select Case _digitTest
Case "0" To "9"
'OK
_digit = CInt(_digitTest)
Case Else
Return String.Empty
End Select
_weight = CInt(IIf(_index Mod 2 = 0, 3, 1))
_digit = _digit * _weight
_sum += _digit
Next
_sum = _sum Mod 10
Dim _check As Integer = 10 - _sum
Return CStr(_check Mod 10)
End Function
Here is the C# from the reflector:
public static string CalculateCheckDigitVB(string Input)
{
int VB$CG$t_i4$S0;
string _temp = Input.Trim().ToUpper();
string _digitTest = string.Empty;
int _sum = 0;
int _weight = 0;
int _digit = 0;
if (_temp == string.Empty)
{
return string.Empty;
}
_temp = _temp.PadLeft(0x11, '0');
int _index = 0;
do
{
_digitTest = _temp.Substring(_index, 1);
string VB$t_string$L0 = _digitTest;
if ((((Operators.CompareString(VB$t_string$L0, "0", false) >= 0) && (Operators.CompareString(VB$t_string$L0, "9", false) <= 0)) ? 1 : 0) != 0)
{
_digit = Conversions.ToInteger(_digitTest);
}
else
{
return string.Empty;
}
_weight = Conversions.ToInteger(Interaction.IIf((_index % 2) == 0, 3, 1));
_digit *= _weight;
_sum += _digit;
_index++;
VB$CG$t_i4$S0 = 0x10;
}
while (_index <= VB$CG$t_i4$S0);
_sum = _sum % 10;
int _check = 10 - _sum;
return Conversions.ToString((int) (_check % 10));
}
Note the
VB$CG$t_i4$S0 = 0x10; inside the loop! O.M.G. Then the fact that someting turned my perfectly good FOR / NEXT loop into a while loop ticked me off. If it was a
good while loop I would not have cared.
Then there is:
_digitTest = _temp.Substring(_index, 1);
string VB$t_string$L0 = _digitTest;
Why this oddly named extra string object for just the range test when there is a perfectly good one right above. I'm having memory issues with perfectly good code on the mobile. Code this be part of that? Namely these objects created internally are doing it to me when we have spent hours reviewing every object and its disposal.
The differences you are noting really are just part of the decompiling problem.
The original:
Public Function CalculateCheckDigitVB(ByVal Input As String) As String Dim _temp As String = Input.Trim.ToUpper Dim _digitTest As String = String.Empty Dim _sum As Integer = 0 Dim _weight As Integer = 0 Dim _digit As Integer = 0 If _temp = String.Empty Then Return String.Empty End If _temp = _temp.PadLeft(17, "0"c) For _index As Integer = 0 To 16 _digitTest = _temp.Substring(_index, 1) Select Case _digitTest Case "0" To "9" 'OK _digit = CInt(_digitTest) Case Else Return String.Empty End Select _weight = CInt(IIf(_index Mod 2 = 0, 3, 1)) _digit = _digit * _weight _sum += _digit Next _sum = _sum Mod 10 Dim _check As Integer = 10 - _sum Return CStr(_check Mod 10) End FunctionHere is the C# from the reflector:public static string CalculateCheckDigitVB(string Input) { int VB$CG$t_i4$S0; string _temp = Input.Trim().ToUpper(); string _digitTest = string.Empty; int _sum = 0; int _weight = 0; int _digit = 0; if (_temp == string.Empty) { return string.Empty; } _temp = _temp.PadLeft(0x11, '0'); int _index = 0; do { _digitTest = _temp.Substring(_index, 1); string VB$t_string$L0 = _digitTest; if ((((Operators.CompareString(VB$t_string$L0, "0", false) >= 0) && (Operators.CompareString(VB$t_string$L0, "9", false) <= 0)) ? 1 : 0) != 0) { _digit = Conversions.ToInteger(_digitTest); } else { return string.Empty; } _weight = Conversions.ToInteger(Interaction.IIf((_index % 2) == 0, 3, 1)); _digit *= _weight; _sum += _digit; _index++; VB$CG$t_i4$S0 = 0x10; } while (_index <= VB$CG$t_i4$S0); _sum = _sum % 10; int _check = 10 - _sum; return Conversions.ToString((int) (_check % 10)); }Note the VB$CG$t_i4$S0 = 0x10; inside the loop! O.M.G. Then the fact that someting turned my perfectly good FOR / NEXT loop into a while loop ticked me off. If it was a good while loop I would not have cared.
Then there is:
_digitTest = _temp.Substring(_index, 1); string VB$t_string$L0 = _digitTest;Why this oddly named extra string object for just the range test when there is a perfectly good one right above. I'm having memory issues with perfectly good code on the mobile. Code this be part of that? Namely these objects created internally are doing it to me when we have spent hours reviewing every object and its disposal.