.NET Core is a cross-platform open source development framework that runs on Windows, Linux, and macOS and cross architecture with support for x86, x64, and ARM. .NET Core was forked from .NET Framework, which technically makes it a subset of the latter, though streamlined line, and modular. .NET Core is a development platform that gives you great flexibility in developing and deploying applications. The new platform frees you from hassles usually experienced during application deployment. Thus, you don't have to worry about managing versions of application runtime on deployment servers.

Currently, in Version 2.0.7, .NET Core includes the .NET runtime with great performance and many features. Microsoft claims it's the fastest version of .NET platform. It has more APIs and more project templates have been added, such as those for developing ReactJS...

With the release of .NET Core 2.0, new templates were added, providing more options for the different application types that can be run on the platform. In addition to the existing project templates, the following single-page application (SPA) templates were added:

• Angular
• ReactJS
• ReactJS and Redux

The console application in .NET Core has a similar structure to that of .NET Framework, whereas ASP.NET Core has several new components, including folders and files, that were not in the previous versions of ASP.NET.

ASP.NET web framework has fully matured over the years, transitioning from web forms to MVC and Web API. ASP.NET core is a new web framework...

Developing .NET Core applications has been made much easier, not only because of the sleekness and robustness of the platform but also through the introduction of Visual Studio Code, a cross-platform editor that runs on Windows, Linux, and macOS. You don't need to have Visual Studio IDE installed on your system before you can create applications on .NET Core.

Visual Studio Code, though not as powerful and features-packed as the Visual Studio IDE, does have in-built productivity tools and features that make creating .NET Core applications with it seamless. You can also install extensions for several programming languages from Visual Studio Marketplace into Visual Studio Code, giving you the flexibility to edit code written in other programming languages.

The C# programming language has matured over the years; more language features and constructs are being added with the release of each version. A language that originally was only being developed in house by Microsoft and run only on Windows operating systems is now open source and cross-platform. This is made possible through .NET Core and Version 7 (7.0 and 7.1) of the language, which added flavors and improved the available features of the language. The roadmap of the language, especially Version 7.2 and 8.0, promises to add more features to the language.

Tuples were introduced into C# language in Version 4 and are used in the simplified form to provide structure with...

ASP.NET Core provides an elegant way of building web applications and APIs that run on Windows, Linux, and macOS, owing to the .NET Core platform's tool and SDK that simplify developing cutting-edge applications and support side-by-side with application versioning. With ASP.NET Core, your applications have a smaller surface area which improves performance as you only have to include the NuGet packages required to run your applications. ASP.NET Core can also be integrated with client-side libraries and frameworks, allowing you to develop web applications using the CSS and JS libraries you are already familiar with.

ASP.NET Core runs with Kestrel, a web server included in the ASP.NET Core project templates. Kestrel is an in-process cross-platform HTTP server implementation based on libuv, a cross-platform asynchronous I/O library that...

The .NET Core platform, though new, is rapidly maturing, with Version 2.0.7 introducing many features and enhancements that simplify building different types of cross-platform applications. In this chapter, we have taken a tour of the platform, introduced the new features of C# 7, and set up a development environment on Ubuntu Linux, while creating our first ASP.NET MVC Core application.

In the next chapter, we will explain what to look out for in order to avoid writing codes that are untestable and we will later walk you through SOLID principles that can help you write testable and quality code.