Nullable types

All C# developer must know what are and how work with value types, e.g. int ,double,char,Datetime,etc. all  values type can not container null values by default, but we can do that support nullables types

For example:

the nullables types are necessary to develop programs more robust, it is not necessary to store data by default as a datatime, the datatime  saves complex values.
For example:

 Run the test

We can use nullable types when we need it

Run the test