Question

Possible Duplicate:
C# using the question mark after a type, for example: int? myVariable; what is this used for?

I saw the ? operator used in many places and tried to Google and StackOverflow it but both search engine exclude it from the query and does not return any good answers.

What is the meaning of this operator? I usually see it after the type declaration like:

int? x;
DateTime? t;

What is the difference between the two following declaration of an int for example:

int? x;
// AND
int x;

Answer 1

This operator is not an operator, but merely the syntactic sugar for a Nullable type:

int? x;

is the same as

Nullable<int> x;