How to sorting multi array by value data? - php

Question

how to sorting multi array by value ?
i have data like this
$num_a = $_POST['num_a']; //get the value data by array num_a[]
$num_b = $_POST['num_b']; //get the value data by array num_b[]
$score = $_POST['score']; //get the value data by array socre[]
for ($i=0; $i < count($num_a); $i++) {
//set total data num_a and num_b with value from score
$ring[($num_a[$i])][($num_b[$i])] = $score[$i];
}
print_r($ring);
//output
Array
(
[0] => Array
(
[1] => 5
)
[1] => Array
(
[2] => 1
)
[2] => Array
(
[0] => 3
)
)
how to display the results sorted by desc, so the results are like this, thank you
the output i want
print_r($ring);
Array
(
[0] => Array
(
[1] => 5
)
[2] => Array
(
[0] => 3
)
[1] => Array
(
[2] => 1
)
)

Answer 1

Try this
$data = [
0 => [ 1 => 5],
1 => [ 2 => 1],
2 => [ 0 => 3],
];
uasort($data, function($a, $b) {
$a = array_pop($a);
$b = array_pop($b);
if ($a == $b)
{
return 0;
}
return ($a < $b) ? 1 : -1;
});
var_dump($data);

Answer 2

You can also use array_multisort (PHP 4, PHP 5)
array_multisort(
array_map(function($_){return reset($_);},$ring),
SORT_DESC,
$ring
);
Test
[akshay#localhost tmp]$ cat test.php
<?php
$data = array(
array( 1 => 5),
array( 2 => 1),
array( 0 => 3),
);
// Input
print_r($data);
// Sort DESC
array_multisort(array_map(function($_){return reset($_);},$data), SORT_DESC, $data);
// Output - sorted array
print_r($data);
?>
Output
[akshay#localhost tmp]$ php test.php
Array
(
[0] => Array
(
[1] => 5
)
[1] => Array
(
[2] => 1
)
[2] => Array
(
[0] => 3
)
)
Array
(
[0] => Array
(
[1] => 5
)
[1] => Array
(
[0] => 3
)
[2] => Array
(
[2] => 1
)
)