how to add nil to nsmutablearray?

Question

NSArray *array = [[NSArray alloc] initWithObjects:@\"ΕΛΤΑ\",
                      @\"ΕΛΤΑ COURIER\", @\"ACS\", @\"ACS ΕΞΩΤΕΡΙΚΟ\", 
                      @\"DHL\",          


        

Answer 1

nil is not an object that you can add to an array: An array cannot contain nil. This is why addObject:nil crashes.

Answer 2

You need to add NSNull class and the best way to do it is like this:

NSArray *array = @[ @"string", @42, [NSNull null] ];

I personally recommend to use a specific value like 0 instead of null or nil in your design of your code, but sometimes you need to add null.

There is a good explanation from this Apple reference.

Answer 3

pass your object through this method when adding to array to avoid attempt to insert nil object from objects crashes.

-(id) returnNullIfNil:(id) obj  {
    return (obj == nil) ? ([NSNull null]) : (obj);
}

[NSNull null] returns an null object which represents nil.

Answer 4

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

Answer 5

nil is used to terminate the array

Answer 6

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.