JSON to NSMutableArray iOS - ios

Question

As a response to a request I get JSON:
{
"letters": {
"A": 0,
"B": 1,
"C": 2,
"D": 3,
"E": 4,
...
}
}
That's my code to acquire this JSON:
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:url]];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
operation.responseSerializer = [AFJSONResponseSerializer serializer];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(#"%#", responseObject);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
// Handle error
}];
I want to fill array with keys (not values) like this:
array[0] = "A"
array[1] = "B"
...?

Answer 1

NSMutableArray *parts = [NSMutableArray new];
NSDictionary *allletters = [responseObject objectForKey:#"letters"];
for (NSString *key in [allletters allKeys])
{
NSString *value = [allletters objectForKey: key];
[parts insertObject:key atIndex:[val intValue]];
}

Answer 2

I haven't tested the code. But it should be something similar to this:
NSDictionary *responseDictionary = (NSDictionary*)responseObject;
NSDictionary *letters = [responseDictionary objectForKey:"letters"];
NSMutableArray *lettersArray = [[NSMutableArray alloc]init];
if ( letters ){
for (NSInteger i = 0; i < letters; ++i)
{
[lettersArray addObject:[NSNull null]];
}
[letters enumerateKeysAndObjectsWithOptions:NSEnumerationConcurrent
usingBlock:^(id key, id object, BOOL *stop) {
[lettersArray replaceObjectAtIndex:[key integerValue] withObject:object]
}]
}

Answer 3

try the following code
NSDictionary *letters = [responseObject objectForKey:"letters"];
NSArray *lettersArray = [letters allKeys];

Answer 4

As you are already using the JSON response serializer, responseObject should be a dictionary.
To get all keys of the sub dictionary letters, do
NSArray *letters = [reponseObject[#"letters"] allKeys];
No need for a mutable array here. But if you want it mutable , do
NSMutableArray *letters = [[reponseObject[#"letters"] allKeys] mutableCopy];