Getting NSCFString objectAtIndexedSubscript with NSLog in cellForRowAtIndexPath

Question

I've finished my app using this method and the last call I'm implementing is a simple JSON response which I need to parse and it is giving me:

[__NSCFString objectAtIndexedSubscript:]: unrecognized selector sent to instance 0x17005caa0'

There are a lot of smililar questions like this on this website but I'm doing everything as they directed but still no luck.
It's a nested JSON in responseObject. I'm getting the responseObject which means the request I'm sending is correct.

[[manager dataTaskWithRequest:req completionHandler:^(NSURLResponse * _Nonnull response, id  _Nullable responseObject, NSError * _Nullable error){
        if (!error) {
            if (response) {
                allResponse = [[NSMutableArray alloc] init];
                allPractice = [[NSMutableArray alloc] init];
                allProvider = [[NSMutableArray alloc] init];

                allFirstName = [[NSMutableArray alloc] init];
                allMiddleName = [[NSMutableArray alloc] init];
                allLastName = [[NSMutableArray alloc] init];
                allPracticeName = [[NSMutableArray alloc] init];

                allResponse = responseObject;
                allPractice = [allResponse valueForKey:@"Practice"];
                allProvider = [allResponse valueForKey:@"Provider"];

                allFirstName = [allProvider valueForKey:@"FirstName"];
                allMiddleName = [allProvider valueForKey:@"MiddleName"];
                allLastName = [allProvider valueForKey:@"LastName"];
                allPracticeName = [allPractice valueForKey:@"PracticeAlias"];

                [self.tableView reloadData];
                [SVProgressHUD dismiss];

            }}

Here is the structure I'm getting as ResponseObjects.

{
    AccountType = 2;
    CreatedBy = smith;
    CreatedDate = "2016-01-25T02:07:42.45";
    DisplayName = ",  ";
    Email = "<null>";
    ErrorMessage = "<null>";
    FirstName = "<null>";
    ID = 1;
    IsActive = 1;
    Password = test;
    Phone = "<null>";
    Practice =     {
PracticeAlias = “SAMPLE MEDICAL GROUP";
};
    PracticeAlias = "<null>";
    PracticeCode = "<null>";
    PracticeID = 1;
Provider =     {
    AccountType = 0;
    CreatedBy = smith;
    LastName = John;
    MiddleName = "";
    FirstName = Smith;
};
    Staff = "<null>";
    lstPractice = "<null>";
    lstProvider = "<null>";
    pageSize = 0;
}

So in cellForRowAtIndexPath when I do this:

NSLog(@"%@", [NSString stringWithFormat:@"%@",allPracticeName[indexPath.row]]);

The app crash with the message I shared above.

Answer 1

allPracticeName is of type NSString (with value "< null >"). You are calling a subscript operator [] on this string:

allPracticeName[indexPath.row]

but NSString has no subscript implementation.

Remove the subscript:

NSLog(allPracticeName);