Array Sorting

sleepydad

is it possible to sort the entire array:

Array ( [key] => Array ( [0] => 1 [1] => 2 [2] => 3 ) [firstname] => Array ( [0] => Sam [1] => Bob [2] => Roger [lastname] => Array ( [0] => Smith [1] => Jones [2] => White )

by descending [key] value to get

Array ( [key] => Array ( [2] => 3 [1] => 2 [0] => 1 ) [firstname] => Array ( [2] => Roger [1] => Bob [0] => Sam [lastname] => Array ( [2] => White [1] => Jones [0] => Smith )

laserlight

Perhaps [man]array_multisort[/man] would do the trick, e.g.,

array_multisort($array['key'], SORT_DESC, $array['firstname'], $array['lastname']);

That said, why do you have this particular array structure? It is usually easier to have an array of records/objects than to have parallel arrays.

sleepydad

Thanks very much. The example is not verbatim how my array is structured. The array that I'm dealing with is actually a bit more complicated, but for the sake of brevity I whittled it down to illustrate my question. It's compiled from a JOIN of two SQL databases and I need the capability to be able to sort the results with an HTML dropdown.

Thanks very much for your reply. I'll give it a try right now.

sleepydad

I just tried your solution, and it worked perfectly! Thanks very much. Now on to task #1,345,523 of this website that I'm developing LOL.

sleepydad

laserlight;11053707 wrote:
Perhaps [man]array_multisort[/man] would do the trick, e.g.,
array_multisort($array['key'], SORT_DESC, $array['firstname'], $array['lastname']);
That said, why do you have this particular array structure? It is usually easier to have an array of records/objects than to have parallel arrays.

I do like your suggestion of records/objects better than mine. Can you tell me how I would sort, based on ['firstname'] ASC the following:

$students=array();

Array ( [0] => Array ( [firstname] => Sam [lastname] => Smith ) [1] => Array ( [firstname] => Roger [lastname] => Jones ) [2] => Array ( [firstname] => Mike [lastname] => Johnson ) )

laserlight

[man]usort[/man] comes in handy for this, e.g.,

usort($students, function($x, $y) { return strcmp($x['firstname'], $y['firstname']); });

It does not look at more concise than the array_multisort call, but the ability to provide a custom comparator rather than rely on predefined sort order and flags makes for greater flexibility, and besides, you don't have to remember to provide all the parallel arrays as arguments.

sleepydad

laserlight;11053717 wrote:
[man]usort[/man] comes in handy for this, e.g.,
usort($students, function($x, $y) { return strcmp($x['firstname'], $y['firstname']); });
It does not look at more concise than the array_multisort call, but the ability to provide a custom comparator rather than rely on predefined sort order and flags makes for greater flexibility, and besides, you don't have to remember to provide all the parallel arrays as arguments.

Again another excellent answer. Thanks very much. One note:

I've been pulling my hair out for the last five hours trying to figure out why your latest suggestion wasn't sorting my list alphabetically. I just happened to browse a post in another forum where someone said that usort is case sensitive. I had one all lower case variable mixed in with others that were upper/lower case and the lower case kept showing at the end when I did a print_r. Once I changed it's capitalization, it worked fine.

Is there another solution that doesn't consider capitalization? Not a big deal if not. Just curious.

Thanks again for all. Terrific answers!

laserlight

sleepydad wrote:
I've been pulling my hair out for the last five hours trying to figure out why your latest suggestion wasn't sorting my list alphabetically. I just happened to browse a post in another forum where someone said that usort is case sensitive. I had one all lower case variable mixed in with others that were upper/lower case and the lower case kept showing at the end when I did a print_r. Once I changed it's capitalization, it worked fine.

Is there another solution that doesn't consider capitalization? Not a big deal if not. Just curious.

The claim that usort is case-sensitive is utter rubbish. usort will sort using the provided comparator. If you want a case-insensitive comparison, provide a case-insensitive comparator, e.g., with the help of [man]strcasecmp[/man].

sleepydad

I'm curious then why the all lowercase return was not alphabetized with the mixed capitalization returns. For example I had "Sam","John","Glen","alvin" that after usort print_r()'d as Glen,John,Sam,alvin, but when I changed alvin to Alvin they sorted correctly including Alvin. Not to challenge you because you've been awesome 🙂 Just for my own knowledge moving forward. Thanks again very much for all of your assistance. I really do appreciate it! BTW, I'm reading up on strcasecmp as soon as I finish typing this reply.

Weedpacket

Because 'a' comes after 'G' (lowercase English letters follow uppercase ones).