Use of undeclared identifier in json for iOS

I am getting a use of undeclared identifier error in my json but I am following the example from http://blog.zachwaugh.com/post/309924609/how-to-use-json-in-cocoaobjective-c

how do I fix this? Yes I am very new to objective-c \ ios :) Thanks

I am putting this code in my view based application in my viewcontroller.m file

The issue is with "SBJSON *parser = [[SBJSON alloc] init];"

 // Create new SBJSON parser object
   SBJSON *parser = [[SBJSON alloc] init];

// Prepare URL request to download statuses from Twitter
NSURLRequest *request = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://twitter.com/statuses/public_timeline.json"]];

// Perform request and get JSON back as a NSData object
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

// Get JSON as a N开发者_Python百科SString from NSData response
NSString *json_string = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];

// parse the JSON response into an object
// Here we're using NSArray since we're parsing an array of JSON status objects
NSArray *statuses = [parser objectWithString:json_string error:nil];

// Each element in statuses is a single status
// represented as a NSDictionary
for (NSDictionary *status in statuses)
{
    // You can retrieve individual values using objectForKey on the status NSDictionary
    // This will print the tweet and username to the console
    NSLog(@"%@ - %@", [status objectForKey:@"text"], [[status objectForKey:@"user"] objectForKey:@"screen_name"]);
}

Try changing the line to SBJsonParser *parser = [[SBJsonParser alloc] init];

Edit:

A way that can be easier is to use the NSString category that SBJSON provides:

NSArray *statuses = (NSArray *)[json_string JSONValue];