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)

Inheriting from classes

The Person type we created earlier implicitly derived (inherited) from System.Object. Now, we will create a class that inherits from Person:

  1. Add a new class named Employee to the PacktLibrary project.
  2. Modify its statements, as shown in the following code:
    using System; 
    namespace Packt.Shared 
    { 
      public class Employee : Person 
      { 
      } 
    }
  3. Add statements to the Main method to create an instance of the Employee class, as shown in the following code:
    Employee john = new Employee  
    { 
      Name = "John Jones",  
      DateOfBirth = new DateTime(1990, 7, 28)  
    };
    john.WriteToConsole();
  4. Run the console application and view the result, as shown in the following output:
    John Jones was born on a Saturday

Note that the Employee class has inherited all the members of Person.

Extending classes

Now, we will add some employee-specific members to extend the class.

  1. In the Employee class, add the following code to define two properties...