Getting the error in JSON parsing in iphone - iphone

Question

I am trying to pars the json data and display in table
My JSON data is like this
{"isError":false,"ErrorMessage":"","Result":{"Count":4,"Data":[{"ContentID":"127_30_1309793318065","ContentTypeID":1,"UserCaption":"Gandhinagar(Kanjurmarg)","UserComment":"central\n","DateRecorded":"\/Date(1309793318000+0530)\/","Data":"","ShareType":true,"Views":0,"PlayTime},{},{},{}];};isError = 0;}
I am prasing like this
-(void)connectionDidFinishLoading:(NSURLConnection *)connection
{
NSString *loginStatus = [[NSString alloc] initWithBytes: [webData mutableBytes] length:[webData length] encoding:NSUTF8StringEncoding];
NSLog(#"%#",loginStatus);
//this is for the getting the data from the server with help of JSON
NSString *json_string = [[NSString alloc] initWithData:webData encoding:NSUTF8StringEncoding];
NSDictionary *result = [json_string JSONValue];
/
//this for holding the Array value which come from the server
NSMutableArray *results = [[NSMutableArray alloc] init];
for (int index = 0; index<[reviewsvalues count]; index++)
{
NSMutableDictionary * value = [reviewsvalues objectAtIndex:index];
ReviewsResult * result = [[ReviewsResult alloc] init];
result.User_Caption = [value objectForKey:#"UserCaption"];
result.ContentType_Id = [value objectForKey:#"DateRecorded"];
result.Average_Rating = [value objectForKey:#"AverageRating"];
//OVER here MY APP GET CRASH
}
}
BUt it get crash and give error
[__NSCFDictionary objectAtIndex:]: unrecognized selector sent to instance

Answer 1

The problem is simple.
reviewsvalues should be an NSDictionary and you should not be calling objectAtIndex: for the reviewsvalues.
Instead you should call valueForKey like
int count = [[reviewsvalues valueForKey:#"Count"] intValue];
NSArray *reviewsArray = [reviewsvalues valueForKey:#"Data"];
int count = [reviewsArray count];
cell.textLabel.text = [[reviewsArray objectAtIndex:indexPath.row] valueForKey:#"ContentID"];
Hope this helps you.
Please let me know if you want more help on this.

Answer 2

You set reviewsvalues = [result objectForKey:#"Result"];
Which means reviewsvalues is now an NSDictionary.
"Result" is a dictionary, not an array:
{"Count":4,"Data":[...]}
NSDictionary doesn't respond to -objectAtIndex:, that's one of NSArray's methods.
You need another step:
NSArray *reviewsArray = [reviewsvalues objectForKey:#"Data"];
and while you are at it, you can use fast enumeration.
for (NSDictionary *review in reviewsArray) {
ReviewsResult * result = [[ReviewsResult alloc] init];
result.User_Caption = [review objectForKey:#"UserCaption"];
result.ContentType_Id = [review objectForKey:#"DateRecorded"];
result.Average_Rating = [review objectForKey:#"AverageRating"];
}
Edit: also, you should know that you've not coded this very defensively. What happens if the data isn't exactly as it is in your example? what happens if a value is missing, like "Data", or "Result"?
Your app should be robust enough to not choke if something slightly unexpected happens.