objective-c json 數據組裝

NSMutableDictionary *dictionary3 = [[NSMutableDictionary alloc] init];
        [dictionary3 setValue:@"Anthony3" forKey:@"First Name"];
        [dictionary3 setValue:@"Robbins3" forKey:@"Last Name"];


        NSMutableDictionary *dictionary2 = [[NSMutableDictionary alloc] init];
        [dictionary2 setValue:@"Anthony2" forKey:@"First Name"];
        [dictionary2 setValue:@"Robbins2" forKey:@"Last Name"];


        NSMutableArray * items = [[NSMutableArray alloc]init ];
        [items addObject:dictionary2];
        [items addObject:dictionary3];


        NSMutableDictionary *dictionary = [[NSMutableDictionary alloc] init];
        [dictionary setValue:@"Anthony" forKey:@"First Name"];
        [dictionary setValue:@"Robbins" forKey:@"Last Name"];
        [dictionary setValue:items forKey:@"items"];

        NSError *error = nil;
        NSData *jsonData = [NSJSONSerialization dataWithJSONObject:dictionary
                                                           options:NSJSONWritingPrettyPrinted
                                                             error:&error];

        if (error){
            NSLog(@"error");
        }
        NSString * param = [[NSString alloc]initWithData:jsonData encoding:NSUTF8StringEncoding];

        NSLog(param);