Decoding Particular Element of JSON In PHP -

i trying decode json

i reading json through stomp. there different json datasets need work out json dataset has come through. reading title.

however there 1 particular dataset having trouble reading

  foreach (json_decode($msg->body,true) $event) {     if(isset($event['schemalocation'])) {     $schedule_id=($event['schedule']['schedule_start_date']);      $signalling_id=($event['schedule']['schedule_segment']['signalling_id']);      echo $schedule_id;     } 

in above example isset function works fine , $schedule_id obtains right answer

however $signalling_id gives error of undefined index:

here dump of part of json (its rather long............).the piece of json signalling_id towards end of json. variable signalling_id appreciated.

    array(7) {     ["schemalocation"]=>     string(72) "http://xml.networkrail.co.uk/ns/2008/train itm_vstp_cif_messaging_v1.xsd"     ["classification"]=>     string(8) "industry"     ["timestamp"]=>     string(13) "1410374918000"     ["owner"]=>     string(12) "network rail"     ["originmsgid"]=>     string(47) "2014-09-10t18:48:38-00:00vstp.networkrail.co.uk"     ["sender"]=>     array(3) {       ["organisation"]=>       string(12) "network rail"       ["application"]=>       string(4) "tops"       ["component"]=>       string(4) "vstp"     }     ["schedule"]=>     array(11) {       ["schedule_id"]=>       string(0) ""       ["transaction_type"]=>       string(6) "create"       ["schedule_start_date"]=>       string(10) "2014-09-10"       ["schedule_end_date"]=>       string(10) "2014-09-10"       ["schedule_days_runs"]=>       string(7) "0010000"       ["applicable_timetable"]=>       string(1) "n"       ["cif_bank_holiday_running"]=>       string(1) " "       ["cif_train_uid"]=>       string(6) "w64017"       ["train_status"]=>       string(1) "1"       ["cif_stp_indicator"]=>       string(1) "o"       ["schedule_segment"]=>       array(1) {         [0]=>         array(20) {           ["signalling_id"]=>           string(4) "5y75"           ["uic_code"]=>           string(0) ""           ["atoc_code"]=>           string(0) ""           ["cif_train_category"]=>           string(2) "ee"           ["cif_headcode"]=>           string(0) ""           ["cif_course_indicator"]=           ............................................  

schedule_segment array, instead of

['schedule']['schedule_segment']['signalling_id']); 

that should be

['schedule']['schedule_segment'][0]['signalling_id']);