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: 34

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

Article: Three Questions That Help You Build a Better Software Architecture

To architect effectively for an MVP, teams must answer three questions in order: Is the business idea worth pursuing? What performance and scalability are needed? How much maintainability and supportability are required? These guide Minimum Viable Architecture decisions. Empirical testing helps reject costly assumptions early and adapt architecture as the MVP evolves.

By Pierre Pureur, Kurt Bittner

Uno Platform 6.3 Adds .NET 10 Preview Support and VS 2026 Readiness

The team behind Uno Platform released version 6.3 of the cross‑platform .NET UI framework, aimed at developers targeting mobile, desktop and WebAssembly using C# and XAML. The update includes early support for .NET 10 (RC1), compatibility with Visual Studio 2026’s new .slnx format, enhanced WebAssembly image‐decoding performance and other refinements.

By Edin Kapić

Google Introduces LLM-Evalkit to Bring Order and Metrics to Prompt Engineering

Google has introduced LLM-Evalkit, an open-source framework built on Vertex AI SDKs, designed to make prompt engineering for large language models less chaotic and more measurable. The lightweight tool aims to replace scattered documents and guess-based iteration with a unified, data-driven workflow.

By Robert Krzaczyński

JUnit 6.0.0 Ships with Java 17 Baseline, Cancellation API, and Kotlin suspend Support

Introducing JUnit 6.0.0: a transformative update that unifies versions, elevates minimum requirements to Java 17, and introduces streamlined support for Kotlin suspend tests. Enjoy enhanced testing performance with the new CancellationToken API, built-in JFR listeners, and upgraded CSV parsing using FastCSV. Embrace the future of testing—migrate today!

By A N M Bazlur Rahman

Presentation: Why Observability Matters (More!) with AI Applications

Sally O'Malley explains the unique observability challenges of LLMs and provides a reproducible, open-source stack for monitoring AI workloads. She demonstrates deploying Prometheus, Grafana, OpenTelemetry, and Tempo with vLLM and Llama Stack on Kubernetes. Learn to monitor critical cost, performance, and quality signals for business-critical AI applications.

By Sally O'Malley

© 2025   Created by Michael Levin.   Powered by

Badges  |  Report an Issue  |  Terms of Service