What is it? mean after type?

Question

Possible duplicate:
curious C # syntax

So, I saw some code, and some of them use? after type, for example:

private Point? loc = null;

So what am I interested in, Point? different from the point (cannot put a question mark at the end of my sentence, or I will confuse you guys ...:]). The language I use is, by the way, C #.

Answer 1

T?is an abbreviation (in C #) for Nullable<T>- therefore, it Point?is another way of writing Nullable<Point>or an example.

. 1.3 4.1 # 3 - , . . System.Nullable<T>. 4 # :) ( , .)

( , , .)

Answer 2

Point? Nullable<Point>. null , struct s.

Answer 3

, null.