C# 0 The Complete Reference

System.Nullable

, where 

T

 must be a non-

nullable value type.

R

EMEMBER

R

EMEMBER

Only value types have nullable equivalents.

A nullable type can be specified two different ways. First, you can explicitly declare 

objects of type 

Nullable

, which is defined in the 

System

 namespace. For example, this 

creates 

int

and

bool

 nullable types:

System.Nullable count;

System.Nullable done;

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PART I

C h a p t e r   2 0 :  

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PART IPART I

The second way to declare a nullable type is much shorter and is more commonly used. 

Simply follow the type name with a 

?

. For example, the following shows the more common 

way to declare a nullable