<!DOCTYPE html>
<html>
<body>

<?php
function myfunction($a,$b)
{
if ($a===$b)
   {
   return 0;
   }
   return ($a>$b)?1:-1;
}

$a1=array("a"=>"red","b"=>"green","c"=>"blue");
$a2=array("a"=>"blue","b"=>"black","e"=>"blue");

$result=array_intersect_ukey($a1,$a2,"myfunction");
print_r($result);
?>


</body>
</html>