Multidimention array with objectAtIndex - objective-c

Question

I try to read a multidimensional array as request from content:
[
{
"content" : {
"parcel" : {
"ServiceParcelEventPostalCode" : "1005",
"ConsigneePostalCode" : "1220 (292)",
"ParcelTypeDescription" : "Paket",
"ReferenceIdentcode" : "1017348010239480212208",
"CustomerShipmentNr" : "N\/A",
"Identcode" : "1017348010239480212208",
"ReferenceNumber" : "D1Lmp8TPN_1",
.......... etc
I'm, trying to get ServiceParcelEventPostalCode without access :
NSString *urlString = #"http://www.post.at/sendungsverfolgung4.php";
NSURL *url = [NSURL URLWithString:urlString];
// URL-Request-Objekt erstellen
NSMutableURLRequest *request = [[NSMutableURLRequest alloc] init];
[request setURL:url];
[request setHTTPMethod:#"GET"];
NSMutableData *body = [NSMutableData data];
NSString *postWerte = [NSString stringWithFormat:#"id=%#", self.textfeld.text];
[body appendData:[postWerte dataUsingEncoding:NSUTF8StringEncoding]];
[request setHTTPBody:body];
// Abfrage ans Web senden und Rückgabe in Variable speichern
NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];
NSString *returnString = [[NSString alloc] initWithData:returnData encoding:NSUTF8StringEncoding];
const char *convert = [returnString UTF8String];
NSString *responseString = [NSString stringWithUTF8String:convert];
NSMutableArray *meinErgebnis = [responseString JSONValue];
NSString *wert1 = [NSString stringWithFormat:#"%#",[[[meinErgebnis objectAtIndex:2] objectAtIndex:0] objectForKey:#"ServiceParcelEventPostalCode"]];

Answer 1

Just follow structure of your JSON. [] in JSON means array, {} means dictionary. If JSON in your example is your responseString:
NSMutableArray *jsonArray = [responseString JSONValue];
NSString *postalCode = nil;
if (jsonArray.count)
{
NSDictionary *elementDict = [jsonArray objectAtIndex:0];
NSDictionary *contentDict = [elementDict objectForKey:#"content"];
NSDictionary *parcelDict = [contentDict objectForKey:#"parcel"];
postalCode = [parcelDict objectForKey:#"ServiceParcelEventPostalCode"];
}