C#/.NET Little Wondres: The Nullable<T> struct

The Nullable&lt;T&gt; is a handy structure that was created to give us a consistent way to handle “optional” instances of value types. Nullable&lt;T&gt; instances can be assigned to null or compared with null, which really is syntactical sugar which creates a default instance or checks the HasValue property respectively. In addition, you can use the GetValueOrDefault() method or the null-coalescing operator (??) to query the value, or provide a substitute if the value was never set.