We can declare like this:
int? i = null;

Hi,

primitive types can't be null. but to reduce the impedance missmatch between database and programing languages like C# MS has come up with the nullable types.

 

Thanks,

Chinna

 

• Nullable types represent value-type variables that can be assigned the value of null.

• The syntax T? is shorthand for System.Nullable<T>, where T is a value type. The two forms are interchangeable.

• Assign a value to a nullable type in the same way as for an ordinary value type,
   for example int? x = 10; or double? d = 4.108;

• Use the System.Nullable.GetValueOrDefault property to return either the assigned value, or the default value for the underlying type if the value is null, for example int j = x.GetValueOrDefault();

  For more information visit this link:
  http://msdn.microsoft.com/en-us/library/1t3y8s4s(VS.80).aspx

  
  

int is value type and therefore cannot be assigned a "null" value. You just have to
declare the variable in the following form -

int? i = null;

Now this is valid.

int is not an object, it is primitive type which i think can not be null. You can set 0 of negative number.

I am not sure what you want to accomplish here. If you can give your motive then we can provide solution for that.