Working with null values
You have seen how reference types are different from value types in how they are stored in memory, as well as how to store primitive values like numbers in
struct variables. But what if a variable does not yet have a value? How can we indicate that? C# has the concept of a
null value, which can be used to indicate that a variable has not been set.
Making a value type nullable
By default, value types like
DateTime must always have a value, hence their name. Sometimes, for example, when reading values stored in a database that allows empty, missing, or
null values, it is convenient to allow a value type to be
null. We call this a nullable value type.
You can enable this by adding a question mark as a suffix to the type when declaring a variable.
Let’s see an example. We will create a new project because some of the null handling options are set at the project level:
- Use your preferred coding tool to add a new Console...