Question

I’m getting an error when trying to display a JSON file in a TableView.

this is my JSON File:

{
    "GetMenuMethodResult": [
        {
            "itemDescription": "Description",
            "itemNumber": 501,
            "itemPrice": 6,
            "itemTitle": "Item1"
        },
        {
            "itemDescription": "Description",
            "itemNumber": 502,
            "itemPrice": 6.35,
            "itemTitle": "Item2"
        },
        {
            "itemDescription": "Description",
            "itemNumber": 503,
            "itemPrice": 5.55,
            "itemTitle": "item 3"
        }
    ]
}

This is my code in Xcode:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return Menu.count;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];
    }

    NSDictionary *menuItem = [Menu objectAtIndex:indexPath.row];  <- error occurs here
    NSString *itemName = [menuItem objectForKey:@"itemTitle"];
    NSString *itemDesc = [[menuItem objectForKey:@"itemDescription"];

    cell.textLabel.text = itemName;
    cell.detailTextLabel.text =itemDesc ;

    return cell;
}

The error occurs here;

NSDictionary *menuItem = [Menu objectAtIndex:indexPath.row];

I’m new to iOS 5, and I’m not sure if the first line of the JSON file (“GetMenuMethodResult”: [) is causing this error:

**[_NSCDictionary objectAtIndex:] unrecognized selector sent to instance**

Rest of the code:

@interface MasterViewController : UITableViewController {
    NSArray *Menu;
}

- (void)fetchMenu;

@end



- (void)fetchMenu
{
    dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
        NSData* data = [NSData dataWithContentsOfURL:
                        [NSURL URLWithString: @"http://"]];

        NSError* error;

        Menu = [NSJSONSerialization JSONObjectWithData:data
                                                 options:kNilOptions
                                                   error:&error];

        dispatch_async(dispatch_get_main_queue(), ^{
            [self.tableView reloadData];
        });
    });
}


- (void)viewDidLoad
{
    [super viewDidLoad];
    [self fetchMenu];
}

Answer 1

objectAtIndex is a method for NSArray. Your Menu object is an NSDictionary. You need to get the array within the Menu dictionary like this:

NSArray *myArray = [Menu objectForKey:@"GetMenuMethodResult"];

and use myArray as the source for your rows.