CSharp Basics HelloWorld

C# Basics: Hello World and Console Output

This lesson walks through a minimal "Hello, World!" program and a few variables.

Related wiki pages:

• Overview: CSharpBible.md
• Basics of Console.WriteLine: CSharp-Basics-ConsoleWriteLine-DateTime.md

Official docs:

• Your first C# program: https://learn.microsoft.com/dotnet/csharp/fundamentals/program-structure/

---

1. Hello World

using System;

namespace HelloWorldProject
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Hello, World!");
        }
    }
}

---

2. Adding variables

using System;

namespace HelloWorldProject
{
    class Program
    {
        static void Main(string[] args)
        {
            int score = 100;
            string name = "Alice";
            double pi = 3.14159;

            Console.WriteLine("Hello, World!");
            Console.WriteLine("Name: " + name);
            Console.WriteLine("Pi: " + pi);
        }
    }
}

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3. Running with .NET SDK

From a terminal:

dotnet new console -n HelloWorldProject
cd HelloWorldProject
# replace Program.cs with one of the examples

dotnet run

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4. Next steps

• Combine this with input from Lesson20.12.2025.md.
• Explore more examples in CSharp-Basics-ConsoleWriteLine-DateTime.md.