<!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>