App crashing because NSArray objectforkey: Objective C - objective-c

Question

I am trying to parse some Json with Objective C.
My problem is that I am getting the correct json back but when I try parse some of the json my app crashes.
// i will use a code from connect to DB tutorial
NSString *strURL = [NSString stringWithFormat:#"http://www.ddproam.co.za/Central/Asset/AssetsWithSerial?Serial=S00000001"];
// to execute php code
NSData *dataURL = [NSData dataWithContentsOfURL:[NSURL URLWithString:strURL]];
// to receive the returend value
NSString *strResult = [[NSString alloc] initWithData:dataURL encoding:NSUTF8StringEncoding];
NSLog(#"Login response:%#",strResult);
NSError *error;
//parse out the json data
NSDictionary* json = [NSJSONSerialization JSONObjectWithData:dataURL //1
options:kNilOptions
error:&error];
NSArray* defineJsonData = [json objectForKey:#"AssetDesc"]; //2
NSLog(#"value: %#", defineJsonData); //3
Here is my json:
[{"AssetID":1,"AssetName":"Asset 1","AssetDesc":"This is a manually inserted Asset","AssetTypeID":1,"AssetTypeDesc":"This is a manually inserted Asset Type"}]
I am trying to get the AssestName out of the string. I must be doing something wrong.

Answer 1

The whole thing is an array containing a dictionary, not a dictionary containing an array...
This is a very dirty way to get the value you want - you want to write something more safe than this. Try checking the type of class returned before you try to use it...
NSArray* json = [NSJSONSerialization JSONObjectWithData:dataURL //1
options:kNilOptions
error:&error];
NSDictionary* defineJsonData = [json lastObject]; //2
NSLog(#"value: %#", [defineJsonData objectForKey:#"AssetDesc"]); //3