Book Image

C# 8.0 and .NET Core 3.0 – Modern Cross-Platform Development - Fourth Edition

By : Mark J. Price
Book Image

C# 8.0 and .NET Core 3.0 – Modern Cross-Platform Development - Fourth Edition

By: Mark J. Price

Overview of this book

In C# 8.0 and .NET Core 3.0 – Modern Cross-Platform Development, Fourth 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 new chapters on Content Management Systems (CMS) and machine learning with ML.NET. The book covers all the topics you need. Part 1 teaches the fundamentals of C#, including object-oriented programming, and new C# 8.0 features such as nullable reference types, simplified switch pattern matching, and default interface methods. Part 2 covers the .NET Standard APIs, such as managing and querying data, monitoring and improving performance, working with the filesystem, async streams, serialization, and encryption. Part 3 provides examples of cross-platform applications you can build and deploy, such as web apps using ASP.NET Core or mobile apps using Xamarin.Forms. The book introduces three technologies for building Windows desktop applications including Windows Forms, Windows Presentation Foundation (WPF), and Universal Windows Platform (UWP) apps, as well as web applications, web services, and mobile apps.
Table of Contents (21 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 as a comma-separated...