1 => string 'id_1=61' (length=7) 2 => string 'id_2=62' (length=7) $arrayBase will have : array (size=3) 0 => string 'id_0=' (length=5) 1 => string 'id_1=' (length=5) 2 => string 'id_2=' (length=5) Then agendasId array will contain only agendasId array (size=3) 0 => string '60' (length=2) 1 => string '61' (length=2) 2 => string '62' (length=2) */ $arrayBase = generateArrayIdNum(count($idPart)); $agendasId = array(); for ($i = 0; $i < count($idPart); $i++) { $agendasId[] = str_replace($arrayBase[$i], '', $idPart[$i]); } //get date $date = htmlspecialchars($_GET['date']); $infos = $agendaManager->getAllActivitiesByDate($agendasId, $date); $gView->dayCalendar($infos, $idUser); //Generate an array because we want to do diff with the other function generateArrayIdNum($length) { $arrayNum = array(); for ($i = 0; $i < $length; $i++) { $arrayNum[] = "id_{$i}="; } return $arrayNum; }