Converting an NSArray of Dictionaries to JSON array in iOS

Question

I need to send an NSArray to the server in the JSON array format. How can I convert it to JSON. This is a sample of my NSArray

Answer 1

First You must change you structure into NSDictionary class and NSArray containing NSDictionary objects, then try JSONKit in iOS 5 serialization works better than standard NSJSONSerialization.

Answer 2

NSDictionary *firstJsonDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                            @"10.010490", @"latitude",
                            @"76.360779", @"longitude",
                            @"30.833334", @"altitude",
                            @"11:17:23", @"timestamp",
                            @"0.00", @"speed",
                            @"0.00", @"distance",
                            nil];

  NSDictionary *secondJsonDictionary = [NSDictionary dictionaryWithObjectsAndKeys:
                            @"10.010490", @"latitude",
                            @"76.360779", @"longitude",
                            @"30.833334", @"altitude",
                            @"11:17:23", @"timestamp",
                            @"0.00", @"speed",
                            @"0.00", @"distance",
                            nil];

NSMutableArray * arr = [[NSMutableArray alloc] init];

[arr addObject:firstJsonDictionary];
[arr addObject:secondJsonDictionary];

NSData *jsonData2 = [NSJSONSerialization dataWithJSONObject:arr options:NSJSONWritingPrettyPrinted error:&error];
NSString *jsonString = [[NSString alloc] initWithData:jsonData2 encoding:NSUTF8StringEncoding];
NSLog(@"jsonData as string:\n%@", jsonString);

Answer 3

Is the service you are calling a RESTful service?

If so, I'd strongly recommend using RestKit. It does object serialization/deserialization. It also handles all the networking underpinnings. Extremely valuable, and well maintained.

Answer 4

You can use the build in JSON functions of iOS or use an external lib e.g. JSONKit to convert your data to JSON

Answer 5

Check this tutorial, JSON in iOS 5.0 was clearly explained (serailization, deserailization).

Answer 6

#import <JSONKit/JSON.h>

NSArray *array = // Your array here.
NSString *json = [array JSONString];

NSLog(@"%@", json);

JSONKit performs significantly better than SBJson and others in my own and the author's benchmarks.