What exactly wrong in this code?
      $user_friends_bday_set = array();
      function isFullDate($target, $array) {
        array_filter($array, function($friendo){
          if(isset($friendo['bdate']) && strlen($friendo['bdate'])>5 ){
            array_push($target, $friendo);
            return $target;
          }//IF
        });//ARRAYFILTER
      };
  $user_friends_bday_set = isFullDate($user_friends_bday_set, $user_friends_arr);
Why $user_friends_bday_set is null?
 
    