how to add nil to nsmutablearray?

NSArray *array = [[NSArray alloc] initWithObjects:@"ΕΛΤΑ",
                      @"ΕΛΤΑ COURIER", @"ACS", @"ACS ΕΞΩΤΕΡΙΚΟ", 
                      @"DHL", @"INTERATTICA", @"SPEEDEX", 
                      @"UPS", @"ΓΕΝΙΚΗ ΤΑΧΥΔΡΟΜΙΚΗ", @"ΜΕΤΑΦΟΡΙΚΕΣ ΕΞΩΤΕΡΙΚΟΥ", nil];

This is working because it has nil at the end.

But I add objects like this: addObject:name etc... So at the end I have to add nil I do this addObhect:nil but when I run the app it still crashes at cellForRowAtIndexPath:

how can I do this work?

Ok, I dont have to add nil

What is the reason that my app crashes then?

Solution 1:

If you must add a nil object to a collection, use the NSNull class:

The NSNull class defines a singleton object used to represent null values in collection objects (which don’t allow nil values).

Assuming "array" is of type NSMutableArray:

....
[array addObject:[NSNumber numberWithInt:2];
[array addObject:@"string"];
[array addObject:[NSNull null]];

Solution 2:

You don't need to call [addObject:nil]

The nil in initWithObjects: is only there to tell the method where the list ends, because of how C varargs work. When you add objects one-by-one with addObject: you don't need to add a nil.

Solution 3:

You can't add nil when you're calling addObject.