Question

try to compare a field returned by web-service and which contains only either the String true or false (YES, it’s STRING and not boolean), so i try to compare it with another string like this :

if ([withOptions isEqualToString:@"true"]) {
               annotation.stationLavage=@"with";
           }else {
               annotation.stationLavage=@"without";
           }

so when withOptions string contains the “true” string, all is ok, and when it contains the “false” string i got this exception in the log :

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSNull isEqualToString:]: unrecognized selector sent to instance 0x2984d68'

i am pretty sure that in all cases, withOptions contains a string value (either “true” or “false”) and it never contains NULL.

Answer 1

i am pretty sure that in all cases,
withOptions contains a string value
(either “true” or “false”) and it
never contains NULL.

Clearly, that assumption is wrong. 🙂

On the line before that if() statement, add NSLog(@"%@ - %@", withOptions, [withOptions class]);

Not that NSNull and NULL are not the same thing; NSNull is a class whose singleton instance represents “no value” in containers (and other things) that don’t accept nil as values.

When that crash occurs, withOptions is referring to an instance of NSNull.