Question

I have a problem. I get an error if the objectAtIndex:x is empty. In my code the user has to insert a code separated by “/” like 32/31/43 or even 32//12. Everything works but if the user insert a single number without the “/” I got the error shown in the picture but I would like to get an alert view that tell the user that the code has been inserted in a wrong format. I hope it’s clear. thanks

Answer 1

Probably the best way to go about it is to check your array after you created it to make sure there are 3 values.

NSArray *componentDepthString = [depthString componentsSeperatedByString:@"/"];
if ([componentDepthString count] == 3) {
    // everything is good and you can continue with your code;
    //  rest of the code;
} else {
    // the user input bad values or not enough values;
    UIAlertView *myAlert = [[UIAlertView alloc] 
                                    initWithTitle:@"can't continue"
                                    message:@"user input bad values"
                                    delegate:self
                                    cancelButtonTitle:@"Cancel"
                                    otherButtonTitles:nil];
    [myAlert show];
    [myAlert release];
}

EDIT: you will have to edit the title and message to say what you want, but that’s the basic idea on how to check for bad data before the error and how to display a warning. You will have to add your own logic how to handle it with the user