Book Image

C# 12 and .NET 8 – Modern Cross-Platform Development Fundamentals - Eighth Edition

By : Mark J. Price
4.6 (14)
Book Image

C# 12 and .NET 8 – Modern Cross-Platform Development Fundamentals - Eighth Edition

4.6 (14)
By: Mark J. Price

Overview of this book

This latest edition of the bestselling Packt series will give you a solid foundation to start building projects using modern C# and .NET with confidence. You'll learn about object-oriented programming; writing, testing, and debugging functions; and implementing interfaces. You'll take on .NET APIs for managing and querying data, working with the fi lesystem, and serialization. As you progress, you'll explore examples of cross-platform projects you can build and deploy, such as websites and services using ASP.NET Core. This latest edition integrates .NET 8 enhancements into its examples: type aliasing and primary constructors for concise and expressive code. You'll handle errors robustly through the new built-in guard clauses and explore a simplified implementation of caching in ASP.NET Core 8. If that's not enough, you'll also see how native ahead-of-time (AOT) compiler publish lets web services reduce memory use and run faster. You'll work with the seamless new HTTP editor in Visual Studio 2022 to enhance the testing and debugging process. You'll even get introduced to Blazor Full Stack with its new unified hosting model for unparalleled web development flexibility.
Table of Contents (18 chapters)
17
Index

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 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. We will create a new project because some of the null handling options are set at the project level:

  1. Use your preferred coding tool to add a new Console...