php怎么按另外一个数组重新排列自身

function array_order(&$ar, $by) {  asort($by);  foreach($by as $k=>$v) {    $r[$k] = $ar[$k];  }  return $ar = $r;}$arr = array(  'a' => 'aa',  'b' => 'bb',  'c' => 'cc',);$sort_by = array(  'a' => 2,  'b' => 3,  'c' => 1,);array_order($arr, $sort_by);print_r($arr);
------解决方案--------------------
array_multisort($sort_by,SORT_ASC,$arr);
print_r($arr);