How to use JSON for an iPhone app?

Question

I am trying to make an weather app, I found a great JSON weather API online. I am using

NSData * data = [NSData dataWithContentsOfURL: [NSURL URLWithString: absoluteURL]];
NSError * error;
NSDictionary * json = [NSJSONSerialization JSONObjectWithData: data //1
  options: kNilOptions 
  error: & error
];
NSLog(@"%@", json);
NSLog([NSString stringWithFormat: @"location: %@", [json objectForKey: @"status"]]);

to get the data, but it wont work, the log returns (null). Can someone plase explain to me how I can get the strings and values of the JSON file? Thanks!

Answer 1

Edit: Change your code from line 3 (including) to:

NSDictionary * json = [NSJSONSerialization JSONObjectWithData:data options:0 error:&error];
NSArray *meta = json[@"objects"];

for (NSDictionary *aDict in meta) {
    NSDictionary *location = aDict[@"location"];
    NSLog(@"%@", location);
}

This NSLog()s all the locations in your JSON response.

If you want the city and country only once you can do the following:

NSDictionary *location = json[@"objects"][0][@"location"];
NSString *country = location[@"country"];
NSString *locality = location[@"locality"];

NSLog(@"country: %@", country);
NSLog(@"locality: %@", locality);

Output:

country: Germany
locality: Hauzenberg

Answer 2

There is no element "status" in the root of your JSON. The json object will contain exactly same hierarchy as your JSON. In your case, it'll look like this:

root (dictionary)
  |
  -- "objects": (array)
        |
        -- (dictionary)
              |
              -- "sources" (array) 
              -- "weather" (dictionary)
...

You get the idea.

Try this:

for (NSDictionary *object in json[@"objects"])
{
    NSLog([NSString stringWithFormat: @"location: %@", object[@"weather"][@"status"]]);
}