Re: Which is better, pass, or not pass by reference?
From: Marcel (neegeenspam_at_hotentottententententoonstellingen.nl)
Date: 10/21/03
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Date: Tue, 21 Oct 2003 11:14:01 +0200
"Randell D." <you.can.email.me@randelld.at.yahoo.com> schreef in bericht
news:cU4lb.138072$6C4.80562@pd7tw1no...
>
> Folks,
>
> I've asked this before but never got any response but its important and I
> thought I'd pitch it again (hopefully a bit clearer)...
>
> One can pass data from one function to another either by passing a copy,
or
> passing by reference.
>
> My understanding of passing by reference (putting the & before a variable
> during the function declaration) means that the original data is used.
>
> My understanding of *not* passing by reference, (thus passing a copy)
> literally
> means creating a copy of the data contained in my variables - thus
doubling
> the memory usage for this data... even if its just a temporary while the
> function is being executed.
>
> I *believed* (past tense) that one should only pass by reference if they
> wanted the child function to change the data and pass the newer values
back
> to the parent function.
>
> I'm now thinking that this is just a feature and not the only usage. I am
> begining to think I should use "pass by reference" nearly all the time in
> order to conserve memory (since I won't be creating copies of my variable
> data in memory).
>
> Would this be good practice? Am I right that passing by reference means
that
> my variable data is not duplicated thus using less memory than if I had
> passed my variable data as a copy?
> --
> All comments + replies please via the newsgroup,
> Thanks,
> Randell D.
Passing by reference is usefull if you want a function to return more than
only one value... a function returns normally only one value (although you
can return an array with multiple results too)...
Using a reference is done if you want to change a var outside the scope of
your function....
Yes, interesting, why not always use call by reference??? Only thing i can
think is that you do not always want to change values outside the
function...
Regards,
Marcel
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