Perhaps I should have post this as my first message to the group, but I will add it anyway for completeness. Or in case someone wants to try Scala out and at least you can grap this template to start pasting code to trying it out for other examples.

object Hello {
  def main(args: Array[String]): Unit = {
println("Hello world.")
}
}

Save above into Hello.scala, then compile and run your program like these:
powerbookg4:tmp zemian$ scalac Hello.scala
powerbookg4:tmp zemian$ scala Hello
Hello world.

Note that Scala main entry program is a "object" instead of "class". "object" in Scala is like a class that define a type, but it force it to be a singleton(only one instance), so it almost like "static" in Java. Your main entry in command line must be an object with the main method defined.


You may turn your source file into a script by enter a expression that invoke the main method on the end of the file, and then run it through "scala" instead of compiling it. For example:

object Hello {
  def main(args: Array[String]): Unit = {
println("Hello world.")
}
}
Hello.main(args)

Note that variable "args" is predefined when you run it as script. To run it, just invoke like this:
powerbookg4:tmp zemian$ scala Hello.scala
Hello world.

Note the difference. 1 no compile. 2 you give scala the script file name, not the type name!


Happy programming!

Views: 33

Happy 10th year, JCertif!

Notes

Welcome to Codetown!

Codetown is a social network. It's got blogs, forums, groups, personal pages and more! You might think of Codetown as a funky camper van with lots of compartments for your stuff and a great multimedia system, too! Best of all, Codetown has room for all of your friends.

When you create a profile for yourself you get a personal page automatically. That's where you can be creative and do your own thing. People who want to get to know you will click on your name or picture and…
Continue

Created by Michael Levin Dec 18, 2008 at 6:56pm. Last updated by Michael Levin May 4, 2018.

Looking for Jobs or Staff?

Check out the Codetown Jobs group.

 

Enjoy the site? Support Codetown with your donation.



InfoQ Reading List

Improved Application Insights Code Optimizations Identify .NET Performance Bottlenecks Automatically

Microsoft is expanding .NET developers’ toolset with enhancements to Code Optimizations. This feature is part of Azure Monitor offering and now works with the .NET Profiler in Application Insights to automatically detect CPU, memory, and threading issues in production apps and give code‑level recommendations to fix them.

By Edin Kapić

Presentation: Questioning Convention: C# as a Shortcut to Startup Velocity

Sam Cox shares a case study on building a startup platform with C#. He explains how C#’s modern, open-source ecosystem, integrated tooling, and robust libraries enabled him to achieve high developer productivity, rapid iteration, and overcome significant performance challenges, ultimately helping the company secure its first paying customer.

By Sam Cox

Hugging Face Brings Open-Source LLMs to GitHub Copilot Chat in VS Code

Hugging Face has introduced a new integration that allows developers to connect Inference Providers directly with GitHub Copilot Chat in Visual Studio Code. The update means that open-source large language models — including Kimi K2, DeepSeek V3.1, GLM 4.5, and others — can now be accessed and tested from inside the VS Code editor, without the need to switch platforms or juggle multiple tools.

By Robert Krzaczyński

Java 25, the Next LTS Release, Delivers Finalized Features and Focus on Performance and Runtime

Oracle has released version 25 of the Java programming language and virtual machine. As the first LTS release since JDK 21, the final feature set includes 18 JEPs, seven of which are finalized having evolved through the incubation and preview processes. Nine of these features are focused on performance and runtime.

By Michael Redlich

Presentation: Accessible Innovation in XR: Maximizing the Curb Cut Effect

Dylan Fox discusses how accessibility drives innovation in extended reality. Learn how the "curb cut effect" applies to XR development, leading to advancements like AI agents, novel inputs, and multisensory experiences that improve user experience for everyone, not just those with disabilities.

By Dylan Fox

© 2025   Created by Michael Levin.   Powered by

Badges  |  Report an Issue  |  Terms of Service