I am trying following code to get google maps api response

```
NSString* apiUrlStr = [NSString stringWithFormat:@"http://maps.googleapis.com/maps/api/directions/json?origin=%@&destination=%@&sensor=false", saddr, daddr];
NSURL* apiUrl = [NSURL URLWithString:apiUrlStr];

NSLog(@"api url: %@", apiUrl);

NSString *apiResponse = [NSString stringWithContentsOfURL:apiUrl encoding:NSStringEncodingConversionAllowLossy error:Nil];

```

I got this apiResponse json data from google api:

```
   {
 "routes" : [
  {
     "bounds" : {
        "northeast" : {
           "lat" : 23.0236292,
           "lng" : 72.60381579999999
        },
        "southwest" : {
           "lat" : 22.990296,
           "lng" : 72.5293059
        }
     },
     "copyrights" : "Map data Â©2015 Google",
     "legs" : [
        {
           "distance" : {
              "text" : "10.8 km",
              "value" : 10797
           },
           "duration" : {
              "text" : "23 mins",
              "value" : 1403
           },
           "end_address" : "35, Shivranjani, Jodhpur, Ahmedabad, Gujarat 380015, India",
           "end_location" : {
              "lat" : 23.0234672,
              "lng" : 72.5293059
           },
           "start_address" : "6, Natvarlal Raval Marg, Archana Society, Bhairavnath, Maninagar, Ahmedabad, Gujarat 380008, India",
           "start_location" : {
              "lat" : 22.990296,
              "lng" : 72.60381579999999
           },
           "steps" : [
              {
                 "distance" : {
                    "text" : "0.9 km",
                    "value" : 898
                 },
                 "duration" : {
                    "text" : "2 mins",
                    "value" : 123
                 },
                 "end_location" : {
                    "lat" : 22.9943614,
                    "lng" : 72.5962808
                 },
                 "html_instructions" : "Head \u003cb\u003enorthwest\u003c/b\u003e on \u003cb\u003eNatvarlal Raval Marg\u003c/b\u003e toward \u003cb\u003eNatvarlal Raval Marg\u003c/b\u003e\u003cdiv style=\"font-size:0.9em\"\u003ePass by Nelsons International School (on the right)\u003c/div\u003e",
                 "polyline" : {
                    "points" : "khikC{lczLMBu@jBSd@}AtDg@hA_@z@o@rAYl@O\\yArCgA|BMXQ`@q@bBm@zAcAjCSf@kArCMZ"
                 },
                 "start_location" : {
                    "lat" : 22.990296,
                    "lng" : 72.60381579999999
                 },
                 "travel_mode" : "DRIVING"
              },
              {
                 "distance" : {
                    "text" : "0.2 km",
                    "value" : 192
                 },
                 "duration" : {
                    "text" : "1 min",
                    "value" : 40
                 },

```

I am using following code to get poly line points

```
   NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"points\":\\\"([^\\\"]*)\\\"" options:0 error:NULL];

   NSTextCheckingResult *match = [regex firstMatchInString:apiResponse options:0 range:NSMakeRange(0, [apiResponse length])];

   NSString *encodedPoints = [apiResponse substringWithRange:[match rangeAtIndex:1]];
   return [self decodePolyLine:[encodedPoints mutableCopy]];

```

but it returns @"" for encodedPoints

is there any problem in regular expression ?