Working with null values
You have now seen how to store primitive values like numbers in 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 int and 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.
- In the
Chapter02folder, create a new folder namedNullHandling. - Add the
NullHandlingfolder to theChapter02workspace. - Create a new Terminal window for the
NullHandlingproject. - Create a new console application project in the
NullHandlingfolder.
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