array_multisort二位數組排序

        $arr = array(
            '0' => array(
                'num1' => 3,
                'num2' => 27
            ),

            '1' => array(
                'num1' => 5,
                'num2' => 50
            ),

            '2' => array(
                'num1' => 4,
                'num2' => 44
            ),

            '3' => array(
                'num1' => 3,
                'num2' => 78
            )
        );
echo "<pre/>";

         foreach ( $arr as $key => $row ){
            $num1[$key] = $row ['num1'];
            $num2[$key] = $row ['num2'];
        }
        print_r($arr);
        array_multisort($num1, SORT_ASC, $num2, SORT_DESC, $arr) ;
        print_r($arr);

 //result:Array([0]=>Array([num1]=>3 [num2]=>78) [1]=>Array([num1]=>3 [num2]=>27) [2]=>Array([num1]=>4 [num2]=>44) [3]=>Array([num1]=>5 [num2]=>50))