Question

The following is encoded JSON data from a PHP webpage.

{
    {
        "news_date" = "2011-11-09";
        "news_id" = 5;
        "news_imageName" = "newsImage_111110_7633.jpg";
        "news_thread" = "test1";
        "news_title" = "test1 Title";
    },
    {
        "news_date" = "2011-11-10";
        "news_id" = 12;
        "news_imageName" = "newsImage_111110_2060.jpg";
        "news_thread" = "thread2";
        "news_title" = "title2";
    },
// and so on...
}

I’d like to grab one buch of info (date/id/image/thread/title), and store it as an instance of a class. However, I have no clue on how to access each object in 2D arrays.
The following is the code I’ve written to test if I can access them, but it doesn’t work.

What would be the problem?

NSURL *jsonURL = [NSURL URLWithString:@"http://www.sangminkim.com/UBCKISS/category/news/jsonNews.php"];
NSString *jsonData = [[NSString alloc] initWithContentsOfURL:jsonURL];
SBJsonParser *parser = [[SBJsonParser alloc] init];
contentArray = [parser objectWithString:jsonData];
NSLog(@"array: %@", [[contentArray objectAtIndex:0] objectAtIndex:0]); // CRASH!!

Answer 1

In JSON terminology, that’s not a two-dimensional array: it’s an array whose elements are objects. In Cocoa terminology, it’s an array whose elements are dictionaries.

You can read them like this:

NSArray *newsArray = [parser objectWithString:jsonData];

for (NSDictionary *newsItem in newsArray) {
    NSString *newsDate = [newsItem objectForKey:@"news_date"];
    NSUInteger newsId = [[newsItem objectForKey:@"news_id"] integerValue];
    NSString *newsImageName = [newsItem objectForKey:@"news_imageName"];
    NSString *newsThread = [newsItem objectForKey:@"news_thread"];
    NSString *newsTitle = [newsItem objectForKey:@"news_title"];

    // Do something with the data above
}