Question

if comment the nslog-line, there is an error:

Semantic Issue: Use of undeclared
identifier ‘alert’

switch ([[array objectAtIndex:0]intValue]) {
    case 2:
        NSLog(@"Allergie alarm");   << commenting this, gives me an error!!!
        UIAlertView *alert = [[UIAlertView alloc]
                              initWithTitle: @"blabal"
                              message: @"balbalb"
                              delegate: nil
                              cancelButtonTitle:@"OK"
                              otherButtonTitles:nil, nil];
        [alert show];
        [alert release];
        break;
    default:
        break;
}

Answer 1

In order to declare a new variable inside a case you need to open a new scope. To open a new scope simply use curly braces as others have already written.