Chapter 15

1. By enabling the C# 8 nullable reference types feature and decorating the reference types in your code, you will dramatically reduce the occurrence of NullReferenceException exceptions in your code.
2. The new succinct syntax to access the last item in an array is [^1], which makes use of the System.Index type.
3. In a switch expression, the discard (_) character is equivalent to default, which is typically used in the switch statement.
4. C# 8 introduced the asynchronous dispose feature to provide an asynchronous behavior when disposing resources. This way, we can await the asynchronous closing operation from the DisposeAsync method and avoid the danger of using the Task.Wait method inside Dispose.
5. The null coalescing assignment ??= is used to avoid the execution of the code on the right side (in our example, the GetOrders() method) of the assignment when the left side (orders) is not null.
6. In order to be iterated with async foreach, a sequence must exhibit...