Question

I am very new to ios development, I am trying to add some values from NSMutableDictionary to NSMutableArray, when I run the code I get this error

2012-05-29 14:09:34.913 iShop[7464:f803] -[__NSCFArray objectForKey:]:
unrecognized selector sent to instance 0x6e423d0 2012-05-29
14:09:34.915 iShop[7464:f803] * Terminating app due to uncaught
exception ‘NSInvalidArgumentException’, reason: ‘-[__NSCFArray
objectForKey:]: unrecognized selector sent to instance 0x6e423d0’
* First throw call stack: (0x13cb022 0x155ccd6 0x13cccbd 0x1331ed0 0x1331cb2 0x2bb7 0x13cce42 0x93b9df 0x139f94f 0x1302b43 0x1302424
0x1301d84 0x1301c9b 0x12b47d8 0x12b488a 0x15626 0x28bd 0x2825)
terminate called throwing an exception(lldb)

below is my code:

-(void) getData:(NSData *) response {
    NSError *error;

    NSMutableDictionary *json = [NSJSONSerialization JSONObjectWithData:response options:kNilOptions error:&error];
    //NSLog(@"%@", json);

    jsonArray = [[NSMutableArray alloc] init];

    jsonArray = [json objectForKey:@"Name"];

    NSLog(@"%@", jsonArray);

}

- (void)viewDidLoad {
    [super viewDidLoad];

    jsonURL = [NSURL URLWithString:@"http://localhost:8888/read_product_list.php"];
    dispatch_async(BgQueue, ^{
        NSData* data = [NSData dataWithContentsOfURL:jsonURL];
        [self performSelectorOnMainThread:@selector(getData:) 
                               withObject:data waitUntilDone:YES];
    });
}

Answer 1

JSONObjectWithData return an object of type id. depending on the structure of your received json data.
The data recieved is eiher NSDictionary or NSArray. In your case I am guessing the top level object is of type NSArray which does not respond to objectForKey