PHP array_multisort无法正常运行

Question

I am trying to sort $ar1 by the descending order values of $ar2. Nothing is happening.

    $ar1 = array($arperc);
        $ar2 = array($arid);
        array_multisort($ar1,$ar2);


print_r($ar1);

What am I missing

Answer 1

If you want to use the elements of $ar2 as sorting keys, you need to change the order of arguments to array_multisort :

array_multisort($ar2, $ar1);

This will sort $ar2 in ascending order, and also change the order of $ar1 elements exactly as the order of $ar2 is changed by the sorting. To change the order to descending:

array_multisort($ar2, SORT_DESC, $ar1);