How to Sort a Multidemensional Array by an Inner Key

How do I sort a multidimensional array by one of the fields of the inner array in PHP?

You need to use usort, a function that sorts arrays via a user defined function. Something like:

function cmp($a, $b)
{
    if ($a["price"] == $b["price"]) {
        return 0;
    }
    return ($a["price"] < $b["price"]) ? -1 : 1;
}

usort($yourArray,"cmp")

Sort PHP multi-dimensional array based on value in inner array?

Thinking,more useful and practical
http://php.net/manual/en/function.sort.php

function array_sort($array, $on, $order=SORT_ASC){

    $new_array = array();
    $sortable_array = array();

    if (count($array) > 0) {
        foreach ($array as $k => $v) {
            if (is_array($v)) {
                foreach ($v as $k2 => $v2) {
                    if ($k2 == $on) {
                        $sortable_array[$k] = $v2;
                    }
                }
            } else {
                $sortable_array[$k] = $v;
            }
        }

        switch ($order) {
            case SORT_ASC:
                asort($sortable_array);
                break;
            case SORT_DESC:
                arsort($sortable_array);
                break;
        }

        foreach ($sortable_array as $k => $v) {
            $new_array[$k] = $array[$k];
        }
    }

    return $new_array;
}

How to use

 $list = array(
   array( 'type' => 'suite', 'name'=>'A-Name'),
   array( 'type' => 'suite', 'name'=>'C-Name'),
   array( 'type' => 'suite', 'name'=>'B-Name')
 );

$list = array_sort($list, 'name', SORT_ASC);

array(3) { [0]=> array(2) { ["type"]=> string(5) "suite" ["name"]=> string(6) "A-Name"    } [2]=> array(2) { ["type"]=> string(5) "suite" ["name"]=> string(6) "B-Name" } [1]=> array(2) { ["type"]=> string(5) "suite" ["name"]=> string(6) "C-Name" } }

How to Sort a Multi-dimensional Array by Value

Try a usort. If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:

function sortByOrder($a, $b) {
    return $a['order'] - $b['order'];
}

usort($myArray, 'sortByOrder');

Starting in PHP 5.3, you can use an anonymous function:

usort($myArray, function($a, $b) {
    return $a['order'] - $b['order'];
});

With PHP 7 you can use the spaceship operator:

usort($myArray, function($a, $b) {
    return $a['order'] <=> $b['order'];
});

Finally, in PHP 7.4 you can clean up a bit with an arrow function:

usort($myArray, fn($a, $b) => $a['order'] <=> $b['order']);

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.

usort($myArray, function($a, $b) {
    $retval = $a['order'] <=> $b['order'];
    if ($retval == 0) {
        $retval = $a['suborder'] <=> $b['suborder'];
        if ($retval == 0) {
            $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
        }
    }
    return $retval;
});

If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual.

Sort multidimensional array based on 2nd element of the subarray

list.sort, sorted accept optional key parameter. key function is used to generate comparison key.

>>> sorted(lst, key=lambda x: x[1], reverse=True)
[['I', 219], ['A', 22], ['P', 14], ['V', 13], ['G', 10], ...]

>>> sorted(lst, key=lambda x: -x[1])
[['I', 219], ['A', 22], ['P', 14], ['V', 13], ['G', 10], ...]

>>> import operator
>>> sorted(lst, key=operator.itemgetter(1), reverse=True)
[['I', 219], ['A', 22], ['P', 14], ['V', 13], ['G', 10], ...]

Sort php multidimensional array by key value

try below solution:

<?php
$array = Array
(
'2' => Array
    (
        '66' => Array
            (
                'id' => 66 ,                  
                'count' => 9
            ),
        '255' => Array
            (
                'id' => 255,                    
                'count' => 20
            )            

    ),

'1' => Array
    (
        '59' => Array
            (
                'id' => 59,                
                'count' => 14
            ),

        '255' => Array
            (
                'id' => 255,                   
                'count' => 73
            )
    )    
);

echo '<pre>';

foreach($array as &$ar){
usort($ar, function($a, $b) {
    return $b['count'] - $a['count'];
});
}

print_r($array);

Output:

Array
(
    [2] => Array
        (
            [0] => Array
                (
                    [id] => 255
                    [count] => 20
                )

            [1] => Array
                (
                    [id] => 66
                    [count] => 9
                )

        )

    [1] => Array
        (
            [0] => Array
                (
                    [id] => 255
                    [count] => 73
                )

            [1] => Array
                (
                    [id] => 59
                    [count] => 14
                )

        )

)

PHP sort 2d array alphabetically by nested value

You should use usort() (i'm assuming PHP 5.3+ here):

usort($your_array, function ($elem1, $elem2) {
     return strcmp($elem1['title'], $elem2['title']);
});

Edit:
I hadn't noticed you wanted to preserve index association, so you actually need to use uasort() instead, with the same parameters.

Edit2:
Here is the pre-PHP 5.3 version:

function compareElems($elem1, $elem2) {
    return strcmp($elem1['title'], $elem2['title']);
}

uasort($your_array, "compareElems");