Subj : Re: only posting is rules
To   : Chris Hoppman
From : Scott Adams
Date : Fri Jan 23 2004 07:51 am

-=> Quoting Chris Hoppman to Scott Adams <=-


SA>  -=> Quoting Tony Master to Scott Adams <=-
SA>         What level of knowledge do you know about them now? I
SA>         ask so not to go WAY basic on you :)

CH> Well, I have program'd with them in the past and sort of done them
CH> right, but the concept is slightly over my head when it comes to them.
CH> Since we have talked last I have went to my libary store and picked up
CH> an old novice pascal  book that had a few examples and goes over them
CH> breifly.

    Take a look at the SWAG archives it has a whole section on pointers.
    I have a link on my website http://users.cybermax.net/~longshot
    on the programming page.

    The main rule of thumb is
    1) Always open and close pointers.  This being critical.
       Use the New function to assign memory for the pointer
       variable.  Using Dispose Function to free up that memory.
       In fact if you don't associate 1 New for 1 Dispose it
       will cause memory leaks.  It can cause problems.  If your
       program crashes its good to have a ExitProc type procedure
       that runs when the program crashes or fails.  This will free
       up any pointers that aren't disposed.  Swag has examples of
       all this.
     2) Only use pointers if your going to transverse large data sets.
       A simple numeric variable of I, J : Integer doesn't need one.
       But an array[700,800] of String[70] might find use for them.

     Pointers were origianlly invented more or less for use in
     B-Trees (Binary trees), Search trees, linked lists using parent
     and child nodes (data).  Again this is covered in SWAG with
     examples.

SA>         I might pull one of my ancient pascal lesson tutorials out
SA>         and get the pointer one I did up for ya.
SA>
SA>         Let me  know..

CH> I see that you postted one.  Which is really nice of you.  I went
CH> ahead and  downloaded the message from this bbs and I will go over it
CH> and see if I can  get a better understanding.

CH> I didn't know about the @ part.

    Its about a decade old I think :)...real ancient and not useful
    when I look at it today.  Back then though it was...
    I hardly use the @ part myself.  Pascal pointers are far easier
    to deal with than C pointers.  If you two have problems with
    specific questions ask away.

    Its 2am so can't give much more brain energy into the posts but
    will help you out when I can..



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