Type: Null

The Null type is used to denote a lack of a value where a value is otherwise expected. Because the Null type has no name, it is impossible to declare a variable of the Null type. The null reference is the only possible value of an expression of Null type. The null reference can always be cast to any reference type. In practice, the programmer can ignore the Null type and just pretend that null is merely a special literal that can be of Any type. In short, null is the only value of the Null type, and the null value is used to represent non-present data.