Book Image

Learn C# Programming

By : Marius Bancila, Raffaele Rialdi, Ankit Sharma
5 (1)
Book Image

Learn C# Programming

5 (1)
By: Marius Bancila, Raffaele Rialdi, Ankit Sharma

Overview of this book

The C# programming language is often developers’ primary choice for creating a wide range of applications for desktop, cloud, and mobile. In nearly two decades of its existence, C# has evolved from a general-purpose, object-oriented language to a multi-paradigm language with impressive features. This book will take you through C# from the ground up in a step-by-step manner. You'll start with the building blocks of C#, which include basic data types, variables, strings, arrays, operators, control statements, and loops. Once comfortable with the basics, you'll then progress to learning object-oriented programming concepts such as classes and structures, objects, interfaces, and abstraction. Generics, functional programming, dynamic, and asynchronous programming are covered in detail. This book also takes you through regular expressions, reflection, memory management, pattern matching, exceptions, and many other advanced topics. As you advance, you'll explore the .NET Core 3 framework and learn how to use the dotnet command-line interface (CLI), consume NuGet packages, develop for Linux, and migrate apps built with .NET Framework. Finally, you'll understand how to run unit tests with the Microsoft unit testing frameworks available in Visual Studio. By the end of this book, you’ll be well-versed with the essentials of the C# language and be ready to start creating apps with it.
Table of Contents (20 chapters)

Ranges and indices

Another convenient functionality introduced in C# 8 is the new syntax to identify single elements or ranges inside a sequence. The language already offers the ability to get or set elements in an array using the square brackets and a numeric index, but this concept has been extended by adding two operators to identify an item from the end of a sequence and to extract a range between two indices.

In addition to the aforementioned operators, the base class library now offers two new system types, System.Index and System.Range, which we will immediately see in action. Let's consider an array of strings containing six country names:

var countries = new[] { "Italy", "Romania", "Switzerland", "Germany", "France", "England" };
var length = countries.Length;

We already know how to use the numeric indexer to get a reference to the first item:

Assert.IsTrue(countries[0] == "Italy");

The...