C # drip -? And ??

By default,. Net cannot assign null values to the value type. You can use the null type to define whether the value type can be empty. For example:

Bool? Mybool = NULL;

In essence, the null type syntax is short for system. nullable <t>. You can also write it like this:

Nullable <bool> mybool = NULL;

 

?? It indicates that when the actual value is null, you can use this operator to assign values to the null type. For example:

Bool? Mybool = NULL;

Bool? Result = mybool ?? False;