I often have to call the Value property when accessing my Linq to SQL objects to check for null values or I get an exception. Can someone please expain these data types (i.e. decimal?, bool?, etc…) that appear to wrap the primitive types?
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I often have to call the Value property when accessing my Linq to SQL objects to check for null values or I get an exception. Can someone please expain these data types (i.e. decimal?, bool?, etc…) that appear to wrap the primitive types?
They are Generics of type
Nullable<T>, and they do wrap primitive types.Why they invented the short form int? is Nullable seems to be down to the standard confusion between succinct and terse C based language developers struggle with.
total.HasValuewill return false, it won’t blow up with a null referencebut
total.Value.ToString();will throw an exception, because theValueproperty of total is null.The
Valueand HasValue properties are read only.means total.Value will return 10.0 and total.HasValue will return true.
It’s a really nice generic, especially for database types, still don’t get the short form though…