Question

You would think this would return an NSString:

NSString *class = NSStringFromClass([[_array objectAtIndex:([_array count] -2)] class]);

NSLog(@"Is a kind of NSString: %@", ([[_class classForCoder] isSubclassOfClass:[NSString class]])? @"Yes" : @"No");    

if ([class isEqualToString:@"MapViewController"]) {
    [_appDelegate.navController0 pushViewController:_userListController animated:YES];

} else {
    [_appDelegate.navController3 pushViewController:_userListController animated:YES];
}

But for some reason it doesn’t, resulting in this crash:

Is a kind of NSString: No
-[NSKeyValueObservationInfo isEqualToString:]: unrecognized selector sent to instance 0x6e69080

Even when I try this:

NSString *class = (NSString *)[[_array objectAtIndex:([_array count] -2)] class];

It still doesn’t return an NSString, resulting in this crash:

Is a kind of NSString: No
+[MapViewController isEqualToString:]: unrecognized selector sent to class 0xd4460

I knew going in, that the last example was a bit of a stretch, but I’m pretty clueless as to why I’m not getting a NSString returned from either one?

Answer 1

When I was accessing the NSString “class” from outside a method, I would get all kinds of wacky errors. so what I did was add a little retain statement:

NSString *class = [NSStringFromClass([[_array objectAtIndex:([_array count] -2)] class]) retain];

and now it’s working like a charm.