$ar = array(
       array("10", 11, 100, 100, "a"),  //10
       array(   1,  2, "2",   3,   1)
      );
array_multisort($ar[0], SORT_ASC, SORT_STRING,
                $ar[1], SORT_NUMERIC, SORT_DESC);
var_dump($ar);


array(2) {
  [0]=>
  array(5) {
    [0]=>
    string(2) "10"
    [1]=>
    int(100)
    [2]=>
    int(100)
    [3]=>
    int(11)
    [4]=>
    string(1) "a"
  }
  [1]=>
  array(5) {
    [0]=>
    int(1)
    [1]=>
    int(3)
    [2]=>
    string(1) "2"
    [3]=>
    int(2)
    [4]=>
    int(1)
  }
}