[Setup] C# Development Environment

1. Download the .NET SDK from dotnet.microsoft.com.
2. Run the installer and follow the on-screen instructions.
3. Run the following in Terminal (or Command Prompt) to verify the installation.

dotnet --version

If a version number is displayed, the installation is complete.

C# programs are managed as projects. You can create, build, and run a project using the dotnet command.

1. Create a project

dotnet new console -n HelloApp
cd HelloApp

dotnet new console creates a console application template. -n HelloApp sets the project name.

The following files are created.

File	Description
Program.cs	The main source file. Write your code here.
HelloApp.csproj	The project configuration file.

2. Review and edit the source code

Open the auto-generated Program.cs and you will see the following code.

// See https://aka.ms/new-console-template for more information
Console.WriteLine("Hello, World!");

Try editing it to something like this.

Console.WriteLine("Hello, World!");
Console.WriteLine("The C# environment is set up successfully.");

3. Run

dotnet run

If Hello, World! and The C# environment is set up successfully. are displayed in the console, you're all set.

Tool	Description
Visual Studio	Microsoft's integrated development environment. The Community edition is free on Windows. Offers rich debugging and code completion features.
Visual Studio Code	A lightweight editor. Installing the C# Dev Kit extension adds code completion and debugging support.
Rider	JetBrains' IDE. Runs on Windows, macOS, and Linux.

It is a good idea to get comfortable with the dotnet run workflow on the command line first, then choose your preferred editor.

Command	Description
dotnet new console	Creates a console application project.
dotnet run	Builds and runs the project.
dotnet build	Builds the project (without running it).
dotnet test	Runs a test project.

If your terminal displays dotnet: command not found, the PATH may not be configured correctly. Follow the steps below to check and fix the issue.

1. Find the command location

Check where the command is located.

which dotnet

If not found, check common installation locations.

ls /usr/local/share/dotnet/dotnet
ls ~/.dotnet/dotnet

2. Check which shell you are using

echo $SHELL

If /bin/zsh is shown, edit ~/.zshrc; if /bin/bash is shown, edit ~/.bashrc.

3. Add to PATH

Once you know the command location, add the PATH to your shell configuration file.

For macOS (zsh):

echo 'export DOTNET_ROOT="/usr/local/share/dotnet"' >> ~/.zshrc
echo 'export PATH="$DOTNET_ROOT:$PATH"' >> ~/.zshrc
source ~/.zshrc

For Linux (bash):

echo 'export DOTNET_ROOT="/usr/local/share/dotnet"' >> ~/.bashrc
echo 'export PATH="$DOTNET_ROOT:$PATH"' >> ~/.bashrc
source ~/.bashrc

DOTNET_ROOT is an environment variable pointing to the .NET SDK installation directory. It is a good practice to set it alongside PATH, as some tools reference it.

For Windows, go to "Advanced System Settings" → "Environment Variables" → "Path" to add the entry. The installer usually sets this automatically, but if you installed manually, check that it is configured correctly.