NSMutableDictionary setObject:forKey: fails to add key

Question

I\'m sure I\'m missing something in a small iPhone program I\'m trying to write, but the code is simple and it compiles without any errors and so I fails to see where the er

Answer 1

Your studentStore instance variable is a pointer to an NSMutableDictionary. By default, it points to nil, meaning it doesn't point to any object. You need to set it to point to an instance of NSMutableDictionary.

- (BOOL)addStudent:(Student *)newStudent
{
    NSLog(@"adding new student");
    if (studentStore == nil) {
        studentStore = [[NSMutableDictionary alloc] init];
    }
    [studentStore setObject:newStudent forKey:newStudent.adminNo];
    return YES;
}