Book Image

C# 9 and .NET 5 – Modern Cross-Platform Development - Fifth Edition

By : Mark J. Price
Book Image

C# 9 and .NET 5 – Modern Cross-Platform Development - Fifth Edition

By: Mark J. Price

Overview of this book

In C# 9 and .NET 5 – Modern Cross-Platform Development, Fifth Edition, expert teacher Mark J. Price gives you everything you need to start programming C# applications. This latest edition uses the popular Visual Studio Code editor to work across all major operating systems. It is fully updated and expanded with a new chapter on the Microsoft Blazor framework. The book’s first part teaches the fundamentals of C#, including object-oriented programming and new C# 9 features such as top-level programs, target-typed new object instantiation, and immutable types using the record keyword. Part 2 covers the .NET APIs, for performing tasks like managing and querying data, monitoring and improving performance, and working with the file system, async streams, serialization, and encryption. Part 3 provides examples of cross-platform apps you can build and deploy, such as websites and services using ASP.NET Core or mobile apps using Xamarin.Forms. The best type of application for learning the C# language constructs and many of the .NET libraries is one that does not distract with unnecessary application code. For that reason, the C# and .NET topics covered in Chapters 1 to 13 feature console applications. In Chapters 14 to 20, having mastered the basics of the language and libraries, you will build practical applications using ASP.NET Core, Model-View-Controller (MVC), and Blazor. By the end of the book, you will have acquired the understanding and skills you need to use C# 9 and .NET 5 to create websites, services, and mobile apps.
Table of Contents (23 chapters)

Working with sets and bags using LINQ

Sets are one of the most fundamental concepts in mathematics. A set is a collection of one or more unique objects. A multiset or bag is a collection of one or more objects that can have duplicates. You might remember being taught about Venn diagrams in school. Common set operations include the intersect or union between sets.

Let's create a console application that will define three arrays of string values for cohorts of apprentices and then perform some common set and multiset operations on them.

  1. Create a new console application project named LinqWithSets, add it to the workspace for this chapter, and select the project as active for OmniSharp.
  2. Import the following additional namespaces:
    using System.Collections.Generic; // for IEnumerable<T>
    using System.Linq; // for LINQ extension methods
  3. In Program, before the Main method, add the following method that outputs any sequence of string variables...