It all depends on what ode you are working on. For desktop apps, the
following will be sufficient:
changes := Nil;
issues := Nil;
terrorists := Nil;
try
changes := TStringList.create;
issues := TIssuesList.create;
terrorists := THardToFind.create;
// stuff is done, planes flown. That type of things.
finally
terrorists.free;
issues.free;
changes.free;
end;
If any of the creates or code in the middle raises an exception, Free will
be called for all the objects.
But after spending many years writing server type apps, I now do this in the
finally block:
finally
try
terrorists.free;
except
// Code to handle the exception
end;
try
issues.free;
except
// Code to handle the exception
end;
try
changes.free;
except
// Code to handle the exception
end;
end;
The main issue here is of any of the Free raises an exception, one or more
objects can be left un-freed, causing a memory leak which is not only hard
to find, but will eventually cause the server to crash with an out of memory
error. Furthermore, wrap the whole lot in a try -- except block to catch
all exceptions and handle them gracefully.
----- Original Message -----
From: "Nahum.Wild" <[EMAIL PROTECTED]>
To: "'NZ Borland Developers Group - Delphi List'" <[EMAIL PROTECTED]>
Sent: Thursday, March 04, 2004 3:36 PM
Subject: [DUG] try..finally : Which way is best?
> Ok so this is something that has bugged me for ages, partly because I
don't
> know and partly because I can't be bother trying to figure it out.
>
> is the following code ok? or should I give each it's own try..finally?
>
> --
>
> changes := TStringList.create;
> issues := TIssuesList.create;
> terrorists := THardToFind.create;
> try
>
> // stuff is done, planes flown. That type of things.
>
> finally
> terrorists.free;
> issues.free;
> changes.free;
> end;
>
> --
>
> I mean what could go wrong in the TStringList.create constructor for
> example? It's not like there should be anything much in there that could
go
> wrong anyway? Because if it does except the destructor will be
immediately
> called - learnt that one the hard way many years ago. As a general rule
of
> thumb I don't put anything significant in a constructor for my own
classes -
> that's what init or setup methods are for.
>
> For the record I've never done it this way, I've always given each their
own
> try..finally.
>
> Thoughts anyone?
>
>
>
> Nahum Wild
> Software Innovator & Process Consultant
> IFE
> PayGlobal
>
> _______________________________________________
> Delphi mailing list
> [EMAIL PROTECTED]
> http://ns3.123.co.nz/mailman/listinfo/delphi
>
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