How to sort an array based on multiple criteria?

Question

I would like to sort by two criteria in an array. The first criterion is the second category and title.

I tried using usort () but it does not work.

Is there a php function to do this?

My original array:

Array
(
    [0] => stdClass Object
    (
        [id] => 1
        [category] => cat1
        [title] => title1
    )
[1] => stdClass Object
    (
        [id] => 3
        [category] => cat2
        [title] => z
    )       
[2] => stdClass Object
    (
        [id] => 2
        [category] => cat1
        [title] => title2
    )
[3] => stdClass Object
    (
        [id] => 4
        [category] => cat2
        [title] => a
    )
)

I would like this:

Array
(
    [0] => stdClass Object
    (
        [id] => 1
        [category] => cat1
        [title] => title1
    )
[1] => stdClass Object
    (
        [id] => 2
        [category] => cat1
        [title] => title2
    )       
[2] => stdClass Object
    (
        [id] => 4
        [category] => cat2
        [title] => a
    )
[3] => stdClass Object
    (
        [id] => 3
        [category] => cat2
        [title] => z
    )               
)

Thanks.

I have not tried much because I found a method:

usort($object, 'sort');
function sort($a,$b){
if($a->category == $b->category){
    if($a->title == $b->title){
        return 0;
    }else{
        return ($a->title < $b->title) ? -1 : 1;
    }
}else{
    return ($a->category < $b->category) ? -1 : 1;
}
}

But it also works with multisort() :

foreach ($object as $sort_key => $sort_row) {
    $category[$sort_key]  = $sort_row->acls_category;
    $title[$sort_key] = $sort_row->acls_title;
}
array_multisort($category, SORT_ASC, $title, SORT_ASC, $object);

Try this nl1.php.net/array_multisort

user1467267
– user1467267

2014-03-15 11:11:03 +00:00
Commented Mar 15, 2014 at 11:11 — user1467267
– user1467267, Commented Mar 15, 2014 at 11:11
What comparison function did you use with usort()?

Lukas
– Lukas

2014-03-15 11:13:32 +00:00
Commented Mar 15, 2014 at 11:13 — Lukas
– Lukas, Commented Mar 15, 2014 at 11:13

Pavlo Kotets · Accepted Answer · 2014-03-15 11:17:20Z

1

$o1 = new stdClass;
$o1->id = 1;
$o1->category = 'cat1';
$o1->title = 'title1';

$o2 = new stdClass;
$o2->id = 3;
$o2->category = 'cat2';
$o2->title = 'z';

$o3 = new stdClass;
$o3->id = 2;
$o3->category = 'cat1';
$o3->title = 'title2';

$o4 = new stdClass;
$o4->id = 4;
$o4->category = 'cat2';
$o4->title = 'a';

$arr = array($o1, $o2, $o3, $o4);

usort($arr, function($a, $b) {
    $catCmp = strcmp($a->category, $b->category);

    if ($catCmp) {
        return $catCmp;
    }

    return strcmp($a->title, $b->title);
});

var_dump($arr);

answered Mar 15, 2014 at 11:17

Pavlo Kotets

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1 Comment

user3185306 Over a year ago

Thank you it also works as you indicate. I added a supplement to indicate how I was going because I did not search enough.

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