Create JSON array in Objective C

Question

I am creating a JSON array using Objective C. I have never done this before but what I would like to do is create the JSON array then make a JSON pair that I use to send back in my NSURLConnection Post body.

I know how to make and send the post body.

NSData *data = // some stuff in here...

        [request setHTTPMethod:@"POST"];
        [request setValue:@"application/json" forHTTPHeaderField:@"Accept"];
        [request setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
        [request setValue:[NSString stringWithFormat:@"%d", [data length]] forHTTPHeaderField:@"Content-Length"];
        [request setHTTPBody:data];

How do I first of all create the JSON array, then how do I make the JSON pair?

score 3 · Answer 1 · answered Nov 18 '13 at 08:47

3

Use Apple's NSJSONSerialization

    NSArray *array = @[@"1",@"2",@"3"];
    NSData *json = [NSJSONSerialization dataWithJSONObject:array options:0 error:nil];

    //back
    array = [NSJSONSerialization JSONObjectWithData:json options:0 error:nil];

answered Nov 18 '13 at 08:47

Daij-Djan

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Lord Zsolt · Answer 2 · 2013-11-18T09:05:33.567

A JSON is basically an NSDictionary converted to NSData. I would suggest just using AFNetworking framework, which takes an NSDictionary as parameter and converts it to a JSON automatically.

But if you want to do the conversion yourself, you can use apples NSJSONSerialization:

NSError *error; 
NSData *jsonData = [NSJSONSerialization dataWithJSONObject:requestParam
                                                   options:NSJSONWritingPrettyPrinted
                                                     error:&error];

If you want to send an array for example you do:

NSArray *requestArray = @[@"1",@"2"];
NSDictionary *requestDictionary = @{@"Array": requestArray};

This will create the following structure:

Array =     (
    1,
    2
);

If you want to later modify the requestDictionary (ex: add extra keys and objects), you just make it mutable and work with it the same way you do with NSMutableDictionaries.

you forgot to JSON encode the stuff.. this is NOT json at all — Daij-Djan, Nov 18 '13 at 08:43
Well, you're right in a way. This isn't a JSON, this is a parameter for AFNetworking methods, I forgot to encode it because I got used to AFNetworking, which does the encoding automatically. — Lord Zsolt, Nov 18 '13 at 09:04

Create JSON array in Objective C

2 Answers2