what is need of nullable value types in c#?

Question

Hi all what is need of nullable value types in c#?

Vulpes · Answer

The main reason for introducing them was to provide a better interface with database columns which can have 'no value' as well as a definite value. When the SQL types correspond to value types in C# (int double DateTime etc) there was no satisfactory way to deal with this before nullable types were invented because a value type must have a definite value - it couldn't be null like reference types such as string. Usually some 'magic value' which either wouldn't (or was very unlikely to) arise in practice had to be used to denote the absence of a definite value.