Pointers in Pascal!!

Zaka E-Lab

unread,

Apr 29, 2008, 7:08:15 AM4/29/08

to

I have something like this:

PStruct = ^Struct;
Struct = record
num : integer;
end;

I have a unit to handle that structure ( is a bit more complicated, but
is a good example), in this unit I have a procedure that deletes (
disposes ) the pointer. How can I know if a pointer are created or not?,
I mean, I don't wont to try to delete something that has not been
created yet, but I don't know how to do it, if that is possible.

Thanks a lot.

Zaka.

Anton

unread,

Jun 13, 2008, 5:33:18 PM6/13/08

to

The Pascal's nil constant is right for that.

Anton

CBFalconer

unread,

Jun 13, 2008, 6:05:56 PM6/13/08

to

Anton wrote:
>
> The Pascal's nil constant is right for that.

Right for what?

If you want to post a followup via groups.google.com, ensure
you quote enough for the article to make sense. Google is onl
an interface to Usenet; it's not Usenet itself. Don't assume
your readers can, or ever will, see any previous articles.

More details at: <http://cfaj.freeshell.org/google/>

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: <http://cbfalconer.home.att.net>
Try the download section.

** Posted from http://www.teranews.com **

Anton

unread,

Jun 19, 2008, 5:29:04 PM6/19/08

to

CBFalconer:

> If you want to post a followup via groups.google.com, ensure
> you quote enough for the article to make sense. Google is onl
> an interface to Usenet; it's not Usenet itself. Don't assume
> your readers can, or ever will, see any previous articles.

All right. But I thought I was replying to a post to this group, and
I didn't post it via google groups...

Original question:
--------------------------

I have a unit to handle that structure ( is a bit more complicated, but
is a good example), in this unit I have a procedure that deletes (
disposes ) the pointer. How can I know if a pointer are created or not?,
I mean, I don't wont to try to delete something that has not been
created yet, but I don't know how to do it, if that is possible.

---------------------------

Anton

CBFalconer

unread,

Jun 19, 2008, 6:54:50 PM6/19/08

to

Anton wrote:
> CBFalconer:
>
>> If you want to post a followup via groups.google.com, ensure

>> you quote enough for the article to make sense. Google is only

>> an interface to Usenet; it's not Usenet itself. Don't assume
>> your readers can, or ever will, see any previous articles.
>
> All right. But I thought I was replying to a post to this group,
> and I didn't post it via google groups...

You are connecting to the usenet group
"comp.lang.pascal.ansi-iso". There are various ways of doing that,
and some hide what they are doing. The best means is to get a
newsreader, such as Thunderbird, slrn, etc. You seem to have one
already, in Xnews.

>
> Original question:
> --------------------------
> I have a unit to handle that structure ( is a bit more complicated,
> but is a good example), in this unit I have a procedure that
> deletes ( disposes ) the pointer. How can I know if a pointer are
> created or not?, I mean, I don't wont to try to delete something
> that has not been created yet, but I don't know how to do it, if
> that is possible.
> ---------------------------

You can't tell after the fact. You have to remember that you
created it.