What You Can Do With C#

Let's get the joke out of the way, because you're going to hear it within four minutes of telling anyone you're learning C#: "Oh, C#? Isn't that just Microsoft Java?" Yes. Kind of. A little. Here's the actual story. Back around 2000, Microsoft wanted a modern, garbage-collected, object-oriented language for their shiny new .NET platform. Java existed and was extremely popular. Microsoft had previously shipped their own version of Java, Sun sued them into the sea, and the whole thing ended in tears and lawyers. So Microsoft did the very sensible, very corporate thing: they hired Anders Hejlsberg , the man who built Turbo Pascal and Delphi, and said: "make us a Java, but ours, and don't get us sued." He did. And then he kept improving it for twenty-five years while Java spent a decade arguing about whether it should add lambdas. So calling C# "Microsoft Java" today is like calling a smartphone "a Microsoft telegraph." Technically, you can trace the lineage. It is also extremely funny to the person being insulted, which is the only thing that matters. So, what can you actually do with this thing? More than you'd think. Let's take the tour. First, the obligatory Hello World Every language tour is legally required to start here. C#'s has changed a lot, which tells you something about the language's whole vibe. The old way, circa 2005, was a ceremony: using System ; namespace MyFirstApp { class Program { static void Main ( string [] args ) { Console . WriteLine ( "Hello, world!" ); } } } Eleven lines to say hello. You needed a namespace , a class , a Main method with a specific signature, and the kind of static void incantation that makes beginners quietly close the tab and go learn Python instead. The modern way (C# 9 and later) is this: Console . WriteLine ( "Hello, world!" ); That's the whole program. The compiler quietly puts all the ceremony back for you behind the scenes. This is C# in a nutshell: it grew up in a buttoned-up enterprise suit, and over twenty years it