Mark Michaelis - Essential C# 7.0

C# is now a well-established language that builds on features found in its predecessor C-style languages (C, C++, and Java), making it immediately familiar to many experienced programmers. Furthermore, the C# programming language can be used to build software components and applications which run on a wide variety of operating systems (platforms).

. The first C# design meeting took place in 1998.

This chapter introduces C# using the traditional HelloWorld program. The chapter focuses on C# syntax fundamentals, including defining an entry point into the C# program. This will familiarize you with the C# syntax style and structure, and it will enable you to produce the simplest of C# programs. Prior to the discussion of C# syntax fundamentals is a summary of managed execution context, which explains how a C# program executes at runtime. This chapter ends with a discussion of variable declaration, writing and retrieving data from the console, and the basics of commenting code in C#.

The best way to learn a new programming language is to write code. The first example is the classic HelloWorld program. In this program, you will display some text to the screen.

shows the complete HelloWorld program; in the following sections, you will compile and run the code.

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class HelloWorld{ static void Main() { System.Console.WriteLine( "Hello. My name is Inigo Montoya." ); }}

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. Refer to the movie The Princess Bride if youre confused about the Inigo Montoya references.

Those experienced in programming with Java, C, or C++ will immediately see similarities. Like Java, C# inherits its basic syntax from C and C++. Syntactic punctuation (such as semicolons and curly braces), features (such as case sensitivity), and keywords (such as class, public, and void) are familiar to programmers experienced in these languages. Beginners and programmers from other languages will quickly find these constructs intuitive.

. When creating C#, the language creators reviewed the specifications for C/C++, literally crossing out the features they didnt like and creating a list of the ones they did like. The group also included designers with strong backgrounds in other languages.

Once you have C# code written, it is time for you to compile and run the code. To accomplish this, we have a choice of which .NET implementation(s) to use - sometimes referred to as the .NET framework(s). Generally, the implementation is packaged into a software development kit (SDK). The SDK includes the compiler, runtime execution engine, the framework of pragmatically accessible functionality that the runtime can access (see API later in the chapter), along with any additional tooling (such as a build engine for automating build steps) that might be bundled with the SDK. Given that C# has been publicly available since the year 2000, there are, in fact, several different .NET frameworks to choose from (see the Multiple .NET frameworks section at the end of the chapter).

For each .NET framework, the installation instructions vary depending on which operating system you are developing on and which .NET framework you select. For this reason, I recommend you visit https://www.microsoft.com/net/download for download and installation instructions, selecting first the .NET framework and then the package to download based on which operating system you will be developing for. While I could provide further details here, the link has the most updated instructions for each combination supported.

If you are unsure about which .NET framework to work with, choose .NET Core by default. It will work on Linux, OS X, and Microsoft Windows and is the implementation where the .NET development teams are applying the majority of their investments. Furthermore, because of the cross-platform capabilities, I will favor .NET Core instructions inline within the chapters.

There are also numerous ways to edit your source code including the most rudimentary of tools like Notepad on Windows, TextEdit on Mac/OS X, or vi on Linux. However, youre likely to want something more advanced so that at least your code is colorized. Any programming editor that supports C# will suffice. However, if you dont already have a preference, I recommend you consider the open source editor, Visual Studio Code (https://code.visualstudio.com/). Or, if you are working on Windows or Mac, consider Microsoft Visual Studio 2017 (or later) - see https://www.visualstudio.com/. Both are available free of charge.