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)

The using declaration

The using declaration is a very convenient syntax equivalent to the try/finally block and provides a deterministic call to the Dispose method. This declaration can be used on all the objects implementing the IDisposable interface:

class DisposableClass : IDisposable
{
    public void Dispose() => Console.WriteLine("Dispose!");
}

We already know that the using declaration deterministically invokes the Dispose method as soon as its closing curly brace is encountered:

void SomeMethod()
{
    using (var x = new DisposableClass())
    {
        //...
    }	// Dispose is called
}

Every time multiple disposable objects need to be used in the same scope, the nested using declarations are nested, causing an annoying triangle-shaped code alignment:

using (var x = new Disposable1())
{
    using (var y = new...