Rank php multidimensional array - php

Question

I'm trying to rank a group of scores. So I've taken the input from a users form and sorted them from largest to smallest in a multidimensional array, so then that I can search the array for the user and retrieve the index to get its "rank" however I appear to be doing something totally wrong! any help on where I'm going wrong would be greatly appreciated, or if there is a better way entirely!
Thank you
PHP Code:
if ( isset( $_POST['submit'] ) ) {
$size = $num_rows;
$p = 0;
$myarray = array();
while ( $p < $size ) {
$myarray[] = array( "user" => $user[$p], "data" => $scanrate[$p] );
$p++;
}
$sort = array();
foreach ( $myarray as $k => $v ) {
$sort['data'][$k] = $v['data'];
}
array_multisort( $sort['data'], SORT_DESC, $myarray );
for ( $i = 0; $i < $num_rows; $i++ ) {
$key = array_search( $i, array_column( $myarray, 'user' ) );
if ( !$key ) {
$key = $num_rows;
}
//this is stored into my database
echo "<br>User " . $user[$i] . " scan rate " . $scanrate[$i] . " rank " . $key;
}
}

Answer 1

You do useless code to do this sort, use the usort() function like :
while($p < $size)
{
$myarray[] = array("user" => $user[$p], "data" => $scanrate[$p]);
$p++;
}
usort($myarray, function($a, $b) {
return $a['data'] - $b['data'];
});
Now your $myarray is sorted and you can search and do what you want.

Answer 2

If you're putting too much effort on smt. with a scripting language, you're definitely doing it wrong...
$sort = array_combine($user, $scanrate);
asort($sort);
// $sort is sorted now, used it as you like:
// List them
foreach ($sort as $user => $scanrate) {
echo "<br>User " . $user . " scan rate " . $scanrate . " rank " . ++$i;
}
// Find the rank of specific user:
echo array_search('matt', array_keys($sort)) + 1;