Working with null values

You have seen 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 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:

1. Use your preferred coding tool to add a new Console Application to the Chapter06 workspace/solution named NullHandling. This section requires a full application with a project file, so you will not be able to use a .NET Interactive notebook.
2. In...