Comment by simonw

Wow:

  void main(String[] args) {
      println("Hello world");
  }

I just saved that as "hello.java" and ran it (using OpenJDK Runtime Environment Homebrew (build 23.0.1) which I happened to have on my Mac already) like this:

  java --enable-preview hello.java

This is SO MUCH less crufty than the old "public static void main(String[] args)" thing. I always felt that was a terrible introduction to programming, when Hello World included a whole chunk of boilerplate and a class that didn't need to exist.