Return True

[RitaG]

Hi.

I have a Sub that calls a Boolean Function and exits the Sub if the Return
value is False. The problem is it's exiting the Sub even if the Return value
is True.

Here's my code.

Private MySub
If Not DownloadFIIDSFi le() Then Exit Sub
'---- Other code here
End Sub

Private Function DownloadFIIDSFi le() As Boolean
Try
'---- Some FTP commands

'--- Check that a file was downloaded
Dim sDirs() As String
sDirs = Directory.GetFi les(DownloadPat h)
iCnt = sDirs.GetLength (0)
If iCnt = 0 Then Return False
'--- Some other code
Return True
Catch e as Exception
'--- Som e error handling
End Try
End Function

I played around with the code e.g.
Dim bOK as Boolean
bOK = DownloadFIIDSFi le()
If bOK = False Then Exit Sub '******** bOK is True but it still went
to execute
'******** "Exit Sub"
statement.

Any suggestions will be greatly appreciated!

Rita

[Joshua Flanagan]

Re: Return True

You will probably have to include more code for anyone to have a chance
at guessing. For example, what does the function return if an exception
is caught? Do you have a Return statement in the exception handler? If
not, VB will probably return False (the default value for a boolean).

My guess is that something unexpected is happening in the code. It
throws an exception, and the exception handler runs. There is no Return
statement, so the function returns the default. And you are never the
wiser, because you caught and ignored the exception.
This a good example of why you should very rarely use "Catch e as
Exception" within a method. See my mini-rant here (and the linked
article which actually contains useful information).

http://flimflan.com/blog/archive/2004/05/20/172.aspx

Joshua Flanagan

[Jon Skeet [C# MVP]]

Re: Return True

RitaG <RitaG@discussi ons.microsoft.c om> wrote:[color=blue]
> I have a Sub that calls a Boolean Function and exits the Sub if the Return
> value is False. The problem is it's exiting the Sub even if the Return value
> is True.[/color]

Could you post a short but complete program which demonstrates the
problem?

See http://www.pobox.com/~skeet/csharp/complete.html for details of
what I mean by that.

--
Jon Skeet - <skeet@pobox.co m>

http://www.pobox.com/~skeet

If replying to the group, please do not mail me too

[Cor Ligthert]

Re: Return True

Rita,
[color=blue]
> If iCnt = 0 Then Return False[/color]

How are you sure that this situation is not done consequently.

Cor

[Olaf Baeyens]

Re: Return True

I do not see a return value after the catch.
You return a value in the case you do not have an expection, but if you do
have an exception, your return value is undefined when I look at your code.
So my guess is that you get an exception and then your result is undefned.

[RitaG]

Re: Return True

Thanks to all for your responses. I'm out of town for 2 weeks and will post
more code/respond to the replies when I get back.

"Joshua Flanagan" wrote:
[color=blue]
> You will probably have to include more code for anyone to have a chance
> at guessing. For example, what does the function return if an exception
> is caught? Do you have a Return statement in the exception handler? If
> not, VB will probably return False (the default value for a boolean).
>
> My guess is that something unexpected is happening in the code. It
> throws an exception, and the exception handler runs. There is no Return
> statement, so the function returns the default. And you are never the
> wiser, because you caught and ignored the exception.
> This a good example of why you should very rarely use "Catch e as
> Exception" within a method. See my mini-rant here (and the linked
> article which actually contains useful information).
> http://flimflan.com/blog/archive/2004/05/20/172.aspx
>
> Joshua Flanagan
>[/color]

[RitaG]

Re: Return True

Thanks Joshua. What you described is what happened. I checked out Jason
Clark's article and will be making some changes!

"Joshua Flanagan" wrote:
[color=blue]
> You will probably have to include more code for anyone to have a chance
> at guessing. For example, what does the function return if an exception
> is caught? Do you have a Return statement in the exception handler? If
> not, VB will probably return False (the default value for a boolean).
>
> My guess is that something unexpected is happening in the code. It
> throws an exception, and the exception handler runs. There is no Return
> statement, so the function returns the default. And you are never the
> wiser, because you caught and ignored the exception.
> This a good example of why you should very rarely use "Catch e as
> Exception" within a method. See my mini-rant here (and the linked
> article which actually contains useful information).
> http://flimflan.com/blog/archive/2004/05/20/172.aspx
>
> Joshua Flanagan
>[/color]