<?phpfunction myfunction($a,$b){if ($a===$b) { return 0; } return ($a>$b)?1:-1;}$a1=array("a"=>"red","b"=>"green","c"=>"blue","yellow");$a2=array("A"=>"red","b"=>"GREEN","yellow","black");$a3=array("a"=>"green","b"=>"red","yellow","black");$result=array_uintersect($a1,$a2,$a3,"myfunction");print_r($result);?>