C# 9.0 Top-Level Programs: Reducing Boilerplate

C# has always been criticized for the “Hello World” ceremony. You needed a namespace, a class, and a static Main method just to print one line. C# 9 Top-Level Programs remove this requirement, bringing C# closer to scripting languages like Python for simple tasks and microservices.

The New Entry Point

// Program.cs (The entire file)
using System;

Console.WriteLine("Hello World!");

// Defining methods at the bottom
void Log(string msg) => Console.WriteLine(msg);

Behind the Scenes

The compiler generates the `Program` class and `Main` method for you. Parameters like `args` are magically available.

// Accessing command line args
if (args.Length > 0)
{
    Console.WriteLine($"Argument: {args[0]}");
}

Key Takeaways

• Ideal for **Azure Functions** and **Console Utilities**.
• Only one file in the project can have top-level statements.
• Great for learning C# without the OO overhead.