ios - How To Get Particular Values From JSON and Plot on Map view Using Objective C? -

i need particular values below json response, values have mentioned below

reg no: (need show callout) lat :  (need use drop pin on map) long :  (need use drop pin on map) name : (need show callout) age : (need show callout) 

note : school of array values getting server increase based on , b , c categories. not static!

{     =     {         school =         (                         {                reg_no = 1;      latitude = "22.345";                 longitude = "-12.4567";                 student =                 (                                         {                         name = "akila";                         age = "23";                         }                 );                 city = "<null>";                 state = tn;             },                                     {                reg_no = 2;                latitude = "22.345";                longitude = "-12.4567";                 student =                 (                                         {                         name = "sam";                         age = "23";                         }                 );                 city = "<null>";                 state = tn;             },                                   {                reg_no = 3;                latitude = "22.345";                longitude = "-12.4567";                 student =                 (                                         {                         name = "lansi";                         age = "23";                         }                 );                 city = "<null>";                 state = tn;             }        );         schoolname = "good school";         categories = school;    }; } 

my code (below code not working) :

 if (data) {             nserror *error;             nsdictionary *json = [nsjsonserialization jsonobjectwithdata:data options:nsjsonreadingmutableleaves | nsjsonreadingmutablecontainers error:&error];             nsdictionary *response = json[@"response"];             (nsdictionary *entry in response[@"a"][@"school"]) {                 nsstring *regno = entry[@"reg_no"];                 nsstring *name = entry[@"student"][@"name"];                 nsstring *age = entry[@"student"][@"age"];                 double latitude = [entry[@"latitude"] doublevalue];                 double longitude = [entry[@"longitude"] doublevalue];                 mkpointannotation *myannotation = [[mkpointannotation alloc] init];                 myannotation.coordinate = cllocationcoordinate2dmake(latitude, longitude);                 myannotation.title = name;                 myannotation.subtitle = [nsstring stringwithformat:@"reg: %@, age: %@", regno, age];                 [mapview addannotation:myannotation];              } 

try nsjsonserialization

nserror *e = nil; nsarray *jsonarray = [nsjsonserialization jsonobjectwithdata: data options: nsjsonreadingmutablecontainers error: &e];  if (!jsonarray) {   nslog(@"error parsing json: %@", e); } else {    for(nsdictionary *item in jsonarray) {       nslog(@"item: %@", item);    } }