Question

I am struggling with the following problem:

I’ve got an API which returns a nested JSON piece.
(I use NSJSONSeralization to parse it)

eg:

 { "thing" = 1,
   "Other thing" = 2,
   "ParentFromList": [{
   "IT" = 3,
   "SecondIT" = 4
 }

How can I use IT and Second it?

I’ve tried:

  NSDictionary *thingy = [[jsonOutput objectForKey:@"ParentFromList"] ObjectForKey:@"IT"];

JsonOutput is also a nsdictionary.
But after running it, it fails with:

  Unrecognized Selector send to instance.

I don’t know how to fix this, help appreciated.

Answer 1

For your data, the outmost object is a NSDictionary instance. The value for the key ParentFromList is an array, i.e. a NSArrayinstance (note the brackets). The arrays first element contains another dictionary instance (note the curly braces).

Furthermore, it’s not ObjectForKey: but objectForKey: (case matters).

So you probably want to write:

NSDictionary *thingy = [ [ [jsonOutput objectForKey: @"ParentFromList"]
                         objectAtIndex: 0]
                       objectForKey: @"IT"];

BTW: Your sample JSON data is both incomplete and not in JSON format (it’s Apple’s property list format).

The correct and complete JSON representation would be:

{
    "thing": 1,
    "Other thing": 2,
    "ParentFromList": [
        {
            "IT": 3,
            "SecondIT": 4
        }
    ]
 }