RE: [PHP] Sorting arrays [SOLVED I THINK]

From: Jake McHenry (linux_at_nittanytravel.com)
Date: 12/14/03 

Date: Sun, 14 Dec 2003 03:22:49 -0500

> -----Original Message-----
> From: Jake McHenry [mailto:linux@nittanytravel.com]
> Sent: Sunday, December 14, 2003 3:14 AM
> To: 'Justin Patrin'
> Cc: 'Php-general'
> Subject: RE: [PHP] Sorting arrays
>
>
> > -----Original Message-----
> > From: Justin Patrin [mailto:papercrane@reversefold.com]
> > Sent: Sunday, December 14, 2003 2:55 AM
> > To: php-general@lists.php.net
> > Subject: Re: [PHP] Sorting arrays
> >
> >
> > Jake McHenry wrote:
> >
> > >>-----Original Message-----
> > >>From: Bronislav Klucka [mailto:Bronislav.Klucka@pro2-soft.com]
> > >>Sent: Sunday, December 14, 2003 2:22 AM
> > >>To: Jake McHenry
> > >>Cc: 'Php-general'
> > >>Subject: RE: [PHP] Sorting arrays
> > >>
> > >>
> > >>
> > >>>>Try to explain a little bit more how the arrays could be
sorted
> > >>>>asscending and by hitting back and submitting form
> > >>
> > >>suddnely sorted
> > >>
> > >>>>descending...
> > >>>>
> > >>>>
> > >>>>Brona
> > >>>>
> > >>>>
> > >>>>>Does anyone know of a way to keep sort from reversing the
> > >>>>
> > >>>>array order?
> > >>>>
> > >>>>>That is kinda fuzzy, let me explain.
> > >>>>>
> > >>>>>I have a couple arrays that I am sorting. If the user hits
the
> > >>>
> > >>>back
> > >>>
> > >>>>>button in their browser, and hits submit again without
> > >
> > > changing
> > >
> > >>>>>anything, the array is sorted again, now in decending order
> > >>>>
> > >>>>instead of
> > >>>>
> > >>>>>ascending as it was the first time around.
> > >>>>>
> > >>>>>The arrays contain dates, and I want them in ascending order.
> > >>>>>
> > >>>>>Is there a way to limit any of the sort routines to ascending
> > >>>
> > >>>only?
> > >>>
> > >>>>>Thanks,
> > >>>>>
> > >>>>>Jake McHenry
> > >>>>>Nittany Travel MIS Coordinator http://www.nittanytravel.com
> > >>>>>
> > >>>>>--
> > >>>>>PHP General Mailing List (http://www.php.net/)
> > >>>>>To unsubscribe, visit: http://www.php.net/unsub.php
> > >>>>>
> > >>>>
> > >>>This page is for adding / editing / removing airline
> reservations.
> > >
> > >
> > >>>What I have done so far is when the user first gets to this
> > >>
> > >>specific
> > >>
> > >>>page, they enter their info. If they put a check in the add
next
> > >>>flight checkbox, then the same form comes up again, each
> > >>
> > >>time adding
> > >>
> > >>>the new info to the same array, building upon the old info.
> > >>
> > >>The arrays
> > >>
> > >>>are then displayed back into form fields where the user can
> > >>
> > >>edit any
> > >>
> > >>>info submitted.
> > >>>
> > >>>I'm sorting the arrays by the flight dates. Each time the
> > >>
> > >>user enters
> > >>
> > >>>a new flight, the array is sorted by date. This is where I'm
> > >
> > > seeing
> > >
> > >>>the problem. The first flight is fine, of course. The
> > >>
> > >>second is fine.
> > >>
> > >>>The third flight entered and all of the flights are now in
> reverse
> > >
> > >
> > >>>order. Then the next flight entered, they're all in the
> > >>
> > >>correct order,
> > >>
> > >>>etc, etc.
> > >>>
> > >>>This problem will most likely happen to my other arrays
> > >>
> > >>further on in
> > >>
> > >>>the project.
> > >>>
> > >>>Is there any way I can make sure that the dates are
> always in the
> > >>>correct order?
> > >>>
> > >>
> > >>I'm pretty confused.... so user puts information into
> form, he/she
> > >>submits it, and you have 1 date, he press back button,
> fill the same
> > >>form again submits form, new date is added and it's in correct
> > >>order, he/she does it for the third and it's in reverse order,
> > >>he/she does it for the fourth and it's in correct
> order... funny...
> > >>could you paste here the sorting part of code?
> > >>
> > >>
> > >>Brona
> > >>
> > >
> > >
> > > The user doesn't even have to hit back, each time the form is
> > > submitted, the data is rearranged in opposite order. Too
> > keep my data
> > > together, here is what the data in the arrays looks
> > > like:
> > >
> > > Array
> > > (
> > > [0] => 01-30-2004|Wilkes-Barre|PA|Salt Lake|UT||Yes|Yes
> > > [1] => 01-16-2004|Wilkes-Barre|PA|Salem|WA||Yes|Yes
> > > [2] => 01-02-2004|Wilkes-Barre|PA|Denver|CO||Yes|Yes
> > > [3] => 01-08-2004|Denver|CO|Wilkes-Barre|PA||No|No
> > > [4] => 01-23-2004|Salem|WA|Wilkes-Barre|PA||No|No
> > > [5] => 02-11-2004|Salt Lake|UT|Wilkes-Barre|PA||No|No
> > > )
> > >
> > >
> > > Then, in my script, after the new data is merged with the
existing
>
> > > array, I sort:
> > >
> > > $array = $_SESSION['Air_Reservations'];
> > > sort($array)
> > >
> > > New output:
> > >
> > > Array
> > > (
> > > [0] => 02-11-2004|Salt Lake|UT|Wilkes-Barre|PA||No|No
> > > [1] => 01-23-2004|Salem|WA|Wilkes-Barre|PA||No|No
> > > [2] => 01-08-2004|Denver|CO|Wilkes-Barre|PA||No|No
> > > [3] => 01-02-2004|Wilkes-Barre|PA|Denver|CO||Yes|Yes
> > > [4] => 01-16-2004|Wilkes-Barre|PA|Salem|WA||Yes|Yes
> > > [5] => 01-30-2004|Wilkes-Barre|PA|Salt Lake|UT||Yes|Yes
> > > )
> > >
> > >
> > > See now? I didn't add a new record this time, but it
> > happens with our
> > > without adding anything new. Each time the array is sorted, this
> > > happens.
> > >
> > >
> > >
> > > Thanks,
> > > Jake
> >
> > It may be that because those are strings they are being sorted
> > strangely. I have two suggestions.
> >
> > 1) Use a sub-associative array or an object for those
> > entries. Delimited
> > strings are ok, but actual structures are generally better.
> >
> > 2) use usort() and specify a function which sorts those dates
> > correctly
> > (sorting those won't sort by year, only month). OR you could
convert
>
> > those dates to UNIX timstamps (with strtotime() possibly) and
> > sort them
> > that way (this may also require using usort()).
> >
> > Try making an array with ONLY dates in it (not the extra
> > info) and see
> > if it sorts those correctly.
> >
> > One more thing: how are you passing these values between pages?
> >
> > --
> > paperCrane <Justin Patrin>
> >
> > --
> > PHP General Mailing List (http://www.php.net/)
> > To unsubscribe, visit: http://www.php.net/unsub.php
> >
>
> Ok, built the test array, here's the code and results:
>
> foreach ($_POST['Change_Date'] as $key => $value)
> {
> $build = "{$_POST['Change_Date'][$key]}|";
> $build .= "{$_POST['Change_Departure_City'][$key]}|";
> $build .= "{$_POST['Change_Departure_State'][$key]}|";
> $build .= "{$_POST['Change_Destination_City'][$key]}|";
> $build .= "{$_POST['Change_Destination_State'][$key]}|";
> $build .=
> "{$_POST['Change_Preferred_Flight_Times'][$key]}|";
> $build .= "{$_POST['Change_Need_Car'][$key]}|";
> $build .= "{$_POST['Change_Need_Hotel'][$key]}";
> $old = array_merge($build, $old);
>
> $test = "{$_POST['Change_Date'][$key]}";
> $array = array_merge($test, $array);
> }
> $_SESSION['Air_Reservations'] = $old;
> }
> print_r($array);
>
>
> I'm seeing that just the dates are doing the exact same thing,
without
> even being sorted. Could this be because of the foreach loop?
>
> The sorting function call is called later after all the arrays are
> built, and I'm seeing the problem before sorting happens.
>
> What is causing this, and why isn't the sorting function working..
> Since it's called later after the arrays are built? Even if this
> problem existed, the when sort is called, shouldn't it sort the data
> into the correct order?
>
> Thanks,
> Jake
>
> --
> PHP General Mailing List (http://www.php.net/)
> To unsubscribe, visit: http://www.php.net/unsub.php
>
>

It was the way I was using array_merge. I was merging the old data
with the new data, I switched the order of the merge and the problem
seems to have gone away. I'm very tired.. Sorry about all this. Guess
I just needed to talk my way through it.

Thanks,

Jake McHenry
Nittany Travel MIS Coordinator
http://www.nittanytravel.com

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