Remove duplicates in associative array by larger date

Hope this helps someone.

            $haystack = array(...); //some array
                        $needles = array('one', 'two', 'three', 'four'); //keys

                        foreach($haystack as $row){

                                $key=implode('',array_intersect_key($row,array_flip($needles))); //make key

                                if(!isset($result[$key])) //if doesn't exist new one
                                {
                                    $result[$key]=$row;
                                }
                                else //if exists compare dates
                                {
                                    $date = strtotime($result[$key]['date']);
                                    $compare = strtotime($row['date']);

                                    if ($date > $compare) {
                                        continue;
                                    }
                                    else
                                    {
                                        $result[$key] = $row;
                                    }
                                } 
                            }