Create a Project

To create a program we need to write source code, and to write source code we need somewhere to put it. While this process may differ slightly between languages, the idea is always the same: gather the code in one place and provide any settings needed.

At this stage, you will be using the C# language, which is part of the open-source .NET framework produced by Microsoft. These tools are free, work cross-platform, and provide us with a great language that we can use to explore programming.

Note

You need somewhere to save your projects. In this book, we will assume you are saving things in your ~/Documents/Code folder.
If you are saving your code elsewhere then make sure to adjust paths as needed.
If you are using WSL (with Ubuntu), you might need to also create a “Documents” folder in your base directory, as it isn’t created by default.

If you haven’t created a Code folder in your documents, then you will need to do this first. Review the mkdir command from manipulating files to do this using the shell.

The dotnet program

With C#, you will use the dotnet program in the Terminal to perform actions like creating a project, adding libraries, building, and running your project. These commands work with project setting files, which are created for you when you use the dotnet program to create a project.

Action	Command	Description
Create a project	dotnet new console	Creates a C# project in the current folder.

The dotnet program sets up a C# project using the dotnet framework. The new argument indicates we want it to create a new project, and console indicates the type of program. In this context, “console” is a synonym for the terminal, and tells the dotnet tool we would like to write a program that is connected to the terminal with the standard streams for input, output, and error messages.

Tip

The key thing to remember from this is the command dotnet new console.

When you run dotnet new console, it will create a few files and folders for you in the current director:

• .vscode is a folder to hold settings for the Visual Studio Code editor we are going to use, which is also produced by Microsoft and designed to work with dotnet. You may not see this folder until you open the project in Visual Studio Code for the first time, which we will do soon.
• Program.cs is the initial source code file for the project, which we will look at in the next section.
• obj is a folder for storing temporary files related to building your program. If you run ls obj/ you will see that there are already some files in this folder — feel free to use cat to explore what they contain.
• Project.csproj is a file containing settings for the project. This will be named the same as the name of the folder you run it in. So if you run dotnet new console in a folder named HelloWorld then the csproj file will be called HelloWorld.csproj.

When you run this command you will have everything you need to get started writing some code.

Project settings

Before we go on, let’s have a look at the structure of a C# project file (the .csproj file). If you open the project file in VS Code, you should see something like this:

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net8.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="splashkit" Version="1.1.4" />
  </ItemGroup>

</Project>

This is an XML document the describes a project. The entries start with the name of the setting in triangular brackets and end with a matching entry with a backslash (/) before the element name. So the text <Project> indicates the start of the project settings, this ends with the <\Project> tag at the end. If you have worked with HTML, this style of markup will be familiar to you.

The Project element contains an attribute called Sdk, indicating the software development kit (SDK) associated with this project. In this case, it tells VS Code that this project is using the "Microsoft.NET.Sdk". This is the SDK associated with the C# programming language.

Within the Project element, we have a PropertyGroup and ItemGroup. The property group sets some properties for the project. The OutputType says that this project will create an executable program (exe). The .NET SDK has a number of versions, so the TargetFramework tells VS Code which version of .NET this project was written for. The next properties, ImplicitUsings and Nullable, set some options that will be used when the programs are built.

The ItemGroup contains a PackackageReference that represents a library that our project has access to.

All of these settings are used by VS Code and the dotnet program, and can be customised for each project.