Question

I try to grab some data with json on ios 5. but i fail…
could someone help me and tell me why it didn’t work out.
here’s my implementation code

define :

#define kBgQueue dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0) //1
#define kLatestKivaLoansURL [NSURL URLWithString:@"http://jaksport.com/jarray.php"] //2

then in the viewdidload :

NSData* data = [NSData dataWithContentsOfURL:
                        kLatestKivaLoansURL];
        [self performSelectorOnMainThread:@selector(fetchedData:)
                               withObject:data waitUntilDone:YES];

this is the function:

- (void)fetchedData:(NSData *)responseData {
    //parse out the json data
    NSError* error;
    NSDictionary* json = [NSJSONSerialization
                          JSONObjectWithData:responseData //1
                                     options:kNilOptions
                                       error:&error];

    NSArray* key = [json objectForKey:@"price"]; //2

    NSLog(@"value: %@", key); //3


  }

this is the json file:

{
    "prices":
        {
        "price":[
            {
                "id":1,
                "name":"Rosie Gradas",
                "beer":4.5,
                "cider":4.5,
                "guinness":4
            },
            {
                "id":2,
                "name":"Wicked Wolf",
                "beer":5,
                "cider":4.5,
                "guinness":4
            },
            {
                "id":3,
                "name":"Cafe Posh",
                "beer":6,
                "cider":5.5,
                "guinness":5.5
            },
            {
                "id":4,
                "name":"My House",
                "beer":16,
                "cider":15.5,
                "guinness":15.5
            }
        ]
    }
}

the nslog always print out null value

Answer 1

The error is in how you acces the objects in your JSON :

{
  "prices":
    {
    "price":[
        {
            "id":1,
            "name":"Rosie Gradas",
            "beer":4.5,
            "cider":4.5,
            "guinness":4
        }
}

Given a JSON like that to access the price array you use a syntax like this

NSArray *price = [[json objectForKey:@"prices"]objecForkey:@"price"];