Question

Why $val is Array(1), but not the numeric value? I expected that $selected as $k => $val should return each line from the array $selected. Thus, $k must be a numeric key (it is) and $val must be corresponding numeric value (but it’s an array instead of simple integer).
So, how do I correctly save sorted keys and values in array $ind and $ranks?

<?php

        $selected = array();

        for ($i=0; $i<5; $i++) {
            $selected[] = array($i => rand(0,5));
        }

        arsort($selected);

        $ind = array();
        $rank = array();
        foreach($selected as $k => $val) {
           $ind[] = $k;
           $rank[] = $val;
        }
?>

UPDATE:
For incstance, this code..

for ($i=0; $i<5; $i++) {
    $selected[$i] = rand(0,5);
}

provided the array:
[0] => 5, [1] => 3, [2] => 2, [3] => 5, [4] => 3

Once I sorted it, initial keys are deleted, right? How can I find initial keys [0]-[4] of randomly generated values after sorting the array?

Answer 1

I think your likely solution is to change

$selected[] = array($i => rand(0,5));

to

$selected[] = rand(0,5);

Doing so will yield $ind and $rank like this:

Array
(
    [0] => 0
    [1] => 3
    [2] => 2
    [3] => 4
    [4] => 1
)
Array
(
    [0] => 4
    [1] => 3
    [2] => 1
    [3] => 0
    [4] => 0
)

The best way to do what you want, is to just use the resultant array, for example:

$selected

Array
(
    [1] => 5
    [2] => 5
    [4] => 4
    [0] => 2
    [3] => 1
)