You still need to worry about "loiterers" though.
eg. Object A refers to object B, which holds a reference back to object A.
Unless one of those references is explictly set to null, before objectA or
object B goes out of scope, the objects are never garbage collected....a
kind of memory leak!
----- Original Message -----
From: "James Sugrue" <[EMAIL PROTECTED]>
To: "'NZ Borland Developers Group - Delphi List'" <[email protected]>
Sent: Friday, July 21, 2006 3:13 PM
Subject: RE: [DUG] Related try..finally question
Not that it applies too much to this example, but this is why I like C#
and
the GC. Don't really have to worry about freeing objects. Only thing you
need to be concerned with is closing data connections and files.
Also,
try
catch
finally
is a better mechanism than
try
try
except
finally
IMHO.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On
Behalf Of Conor Boyd
Sent: Friday, 21 July 2006 2:53 p.m.
To: NZ Borland Developers Group - Delphi List
Subject: RE: [DUG] Related try..finally question
But all your object creation shouldn't really be inside the try's for a
start.
When you call a constructor, and there's an exception inside the
constructor, you're guaranteed that Delphi will tidy up the partially
created instance.
It gets a bit verbose, but IMHO the correct form is as follows:
Something := TSomething.Create(nil);
Try
X := TX.Create(blah); //for some reason crashes here
Try
Y := TY.Create();
Try
//Do Something
Finally
FreeAndNil(y); //will throw exception (?) because was
never created
End;
Finally
FreeAndNil(X);
End;
finally
FreeAndNil(Something);
End;
Don't get me wrong, I don't often go too far down this route, preferring
instead to refactor into smaller methods for a start.
Dennis' is an interesting suggestion, tho'. I will look into that.
Cheers,
C.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of James Sugrue
That's an interesting one. I guess you're talking about something like
this?
Try
Something := TSomething.Create(nil);
X := TX.Create(blah); //for some reason crashes here
Y := TY.Create();
Finally
FreeAndNil(Something);
FreeAndNil(X);
FreeAndNil(y); //will throw exception (?) because was never created
End;
If so then you could just
If (something <> nil) then
FreeAndNil(something);
??
(apologies for any coding errors, haven't done much Delphi recently)
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