PHP 数组函数 array_udiff()

<?php
   function call_back_function($v1,$v2) {
      if ($v1 === $v2) {
         return 0;
      }
      return 1;
   }
   $array1 = array("a"=>"orange","b"=>"mango","c"=>"banana");
   $array2 = array("a"=>"orange","b"=>"mango","c"=>"apple");

   print_r(array_udiff_assoc($array1,$array2,"call_back_function"));
?>