php - convert coordinates to json for upload to database -

i trying convert user's location json before can insert mysql database php, can help? new @ this, code below:

project detail: trying create code will:

• on first launch create user id
• collect location of device
• convert user id , longitude/latitude json
• print json in label "label1"
• then send json mysql database

right now, no coordinates or user id appearing on label, help?

this viewcontroller.m

#import "viewcontroller.h"  @interface viewcontroller () {     cllocationmanager *locationmanager; } @end  @implementation viewcontroller  - (void)viewdidload { [super viewdidload]; self.mapview.delegate = self;  locationmanager = [[cllocationmanager alloc] init]; [locationmanager setdelegate:self]; [locationmanager setdistancefilter:kcldistancefilternone]; [locationmanager setdesiredaccuracy:kcllocationaccuracybest];  [locationmanager startupdatinglocation]; nslog(@" lat: %f",locationmanager.location.coordinate.latitude); nslog(@" lon: %f",locationmanager.location.coordinate.longitude);  //   request use on ios 8 if (floor(nsfoundationversionnumber) <= nsfoundationversionnumber_ios_7_1) {     [self.mapview setshowsuserlocation:yes]; } else {     [locationmanager requestwheninuseauthorization]; }   if ([[nsuserdefaults standarduserdefaults] boolforkey:@"haslaunchedonce"]) {     //app has launched } else {     //first launch     nsstring *identifierstring = [[nsuuid uuid] uuidstring];     [[nsuserdefaults standarduserdefaults] setobject:identifierstring forkey:@"uuidkey"];     [[nsuserdefaults standarduserdefaults] synchronize]; }  nsurl *jsonfileurl = [nsurl urlwithstring:@"http://random.name/service.php"]; nsurlrequest *urlrequest = [[nsurlrequest alloc] initwithurl:jsonfileurl]; [nsurlconnection connectionwithrequest:urlrequest delegate:self];  }  #pragma mark nsurlconnectiondataprotocol methods  - (void)connection:(nsurlconnection *)connection didreceiveresponse:(nsurlresponse *)response { _downloadeddata = [[nsmutabledata alloc] init]; }  - (void)connection:(nsurlconnection *)connection didreceivedata:(nsdata *)data { [_downloadeddata appenddata:data]; }  - (void)connectiondidfinishloading:(nsurlconnection *)connection {     nsmutablearray *_locations = [[nsmutablearray alloc] init];  // parse json came in nserror *error; nsarray *jsonarray = [nsjsonserialization jsonobjectwithdata:_downloadeddata options:nsjsonreadingallowfragments error:&error];  cllocationcoordinate2d coordinate; // loop through json objects, create question objects , add them our questions array (int = 0; < jsonarray.count; i++) {     nsdictionary *jsonelement = jsonarray[i];     mkpointannotation* marker = [[mkpointannotation alloc] init];      marker.title = jsonelement[@"name"];     marker.subtitle = jsonelement[@"address"];     coordinate.latitude = [jsonelement [@"latitude"] doublevalue];     coordinate.longitude = [jsonelement [@"longitude"] doublevalue];      marker.coordinate = coordinate;     // add question locations array     [_locations addobject:marker];      nsdictionary* info = [nsdictionary dictionarywithobjectsandkeys:                           [jsonelement objectforkey:@"name"], @"uuidkey",                           [jsonelement objectforkey:@"latitude"], @" lat: %f",                           [jsonelement objectforkey:@"longitude"], @"lon: %f",                           nil];      //convert object data     nsdata* jsondata = [nsjsonserialization datawithjsonobject:info                                                        options:nsjsonwritingprettyprinted                                                          error:&error];      //print out data contents     label1.text = [[nsstring alloc] initwithdata:jsondata                                              encoding:nsutf8stringencoding];      } }  - (void)locationmanager:(cllocationmanager *)manager didchangeauthorizationstatus:(clauthorizationstatus)status { if (status == kclauthorizationstatusauthorizedwheninuse) {     [self.mapview setshowsuserlocation:yes]; } }