Appending data from several url JSON calls - into one NSDictionary - ios

Question

So, i have a loop where i repeatedly call an url, which returns contacts in JSON format.
Since i call the url more than once, i want to add it all up, an ultimately end up with a NSDictionary, containing contacts for all the url calls.
What i'm doing now, is appending the data for each iteration:
NSData *response = [NSURLConnection sendSynchronousRequest:request
returningResponse:nil error:nil];
[data appendData:response];
and when the loop is over i try to make it into a NSDictionary:
// Loop over - create Dict from all the data.
NSDictionary *JSONDataFinal = [NSJSONSerialization JSONObjectWithData:data
options:0 error:&error2];
I get an error: "garbage at end" and believe the approach is wrong, since it doesn't know how to put data from each consecutive call into the same key, and not create a key for each call.
Should i create a Dictionary for each iteration - and combine them in the end?

Answer 1

You can append data to a NSMutableDictionary after each call.
NSMutableDictionary* jsonDict = [[NSMutableDictionary alloc] init];
for (...) {
...
NSData *response = [NSURLConnection sendSynchronousRequest:request
returningResponse:nil error:nil];
NSDictionary *JSONData = [NSJSONSerialization JSONObjectWithData:data
options:0 error:&error2];
[jsonDict addEntriesFromDictionary:JSONData];
}

Answer 2

Create different dictionary for each json data and store in main array like this:
NSMutableArray *arrAllContacts = [NSMutableArray array];
//here arrJsonURL which stores all url for contacts
for(int i=0; i<[arrJsonURL count]; i++)
{
//create request
...............
NSData *response = [NSURLConnection sendSynchronousRequest:request
returningResponse:nil error:nil];
[data appendData:response];
NSError *error = nil;
//get dictionary from json data
NSDictionary *dictContact = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
[arrAllContacts addObject:dictContact];
}