IOS5 json使用方法

解析json成dic對象    -(void)fetchedData:(NSData*)responseData {//parse out the json dataNSError* error;      NSDictionary* json =[NSJSONSerialization           JSONObjectWithData:responseData //1             options:kNilOptions           error:&error];         NSArray* latestLoans =[json objectForKey:@"loans"]; //2         NSLog(@"loans: %@", latestLoans); //3  }    把對象產生json string  //build an info object and convert to json  NSDictionary* info =[NSDictionary dictionaryWithObjectsAndKeys:[loan objectForKey:@"name"],       @"who",    [(NSDictionary*)[loan objectForKey:@"location"]       objectForKey:@"country"],       @"where",    [NSNumber numberWithFloat: outstandingAmount],       @"what",    nil];     //convert object to data  NSData* jsonData =[NSJSONSerialization dataWithJSONObject:info     options:NSJSONWritingPrettyPrinted error:&error];    //print out the data contents  NSString *str = [[NSString alloc] initWithData:jsonData                                            encoding:NSUTF8StringEncoding];