Cant access serialized JSON data (NSJSONSerialization)

Question

I get this JSON from a web service:

{
    "Respons": [{
        "status": "101",
        "uid": "0"
    }]
}

I have tried to access the data with the following:

NSError* error;

//Response is a NSArray declared in header file.
self.response = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error];

NSString *test = [[self.response objectAtIndex:0] objectForKey:@"status"]; //[__NSCFDictionary objectAtIndex:]: unrecognized selector sent to instance
NSString *test = [[self.response objectForKey:@"status"] objectAtIndex:0]; //(null)

But none of them work, if i NSLog the NSArray holding the serialized data, this i what i get:

{
Respons = (
    {
        status = 105;
        uid = 0;
    }
);
}

How do i access the data?

See json.org. Learn how to read the JSON (it takes about 10 minutes to learn). Then understand how decoded JSON dumps with NSLog (almost like the original JSON, only `()` is used instead of `[]` for an array and not everything is quoted). — Hot Licks, Aug 27 '13 at 19:55
possible duplicate of [Accessing JSON data inside an NSDictionary generated from NSJSONSerialization](http://stackoverflow.com/questions/8588264/accessing-json-data-inside-an-nsdictionary-generated-from-nsjsonserialization) — Hot Licks, Aug 27 '13 at 19:56
@HotLicks Im perfectly capable of reading and writing JSON, have been using it for years in web development. — user1359448, Aug 29 '13 at 14:02

score 3 · Accepted Answer · answered Aug 27 '13 at 19:06

3

Your JSON represents a dictionary, for whom the value associated with the Respons key is an array. And that array has a single object, itself a dictionary. And that dictionary has two keys, status and uid.

So, for example, if you wanted to extract the status, I believe you need:

NSArray *array = [self.response objectForKey:@"Respons"];
NSDictionary *dictionary = [array objectAtIndex:0];
NSString *status = [dictionary objectForKey:@"status"];

Or, in latest versions of the compiler:

NSArray *array = self.response[@"Respons"];
NSDictionary *dictionary = array[0];
NSString *status = dictionary[@"status"];

Or, more concisely:

NSString *status = self.response[@"Respons"][0][@"status"];

answered Aug 27 '13 at 19:06

Rob

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Thanks for the great answer, when i try to compare `status` with a string i get the following warning: Comparison of distinct pointer types 'NSString *' 'char *' Code: NSDictionary *test = [NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error]; NSArray *array = test[@"Respons"]; NSDictionary *dictionary = array[0]; NSString *status = dictionary[@"status"]; NSLog(@"%@", status); if (status == "100") { // } else { // } – user1359448 Aug 29 '13 at 14:08
@user1359448 Two problems: 1. You don't compare strings with `==` operator; you use `isEqualToString`. 2. You forgot the `@` in `@"100"`. Thus, it should be `if ([status isEqualToString:@"100"]) ...`. Either that or `if ([status integerValue] == 100) ...`, which converts the string to a number (avoiding hassles if there was a space in there or something weird like that). – Rob Aug 29 '13 at 15:22

score 1 · Answer 2 · answered Aug 27 '13 at 19:06

1

Your top level object isn't an array, it's a dictionary. You can easily bypass this and add the contents of that key to your array.

self.response = [[NSJSONSerialization JSONObjectWithData:data options:kNilOptions error:&error] objectForKey:@"Respons"];

answered Aug 27 '13 at 19:06

Mick MacCallum

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Cant access serialized JSON data (NSJSONSerialization)

2 Answers2