Hello World Scala

For this you need an IDE that supports Scala – I suggest getting the eclipse bundle from here: http://scala-ide.org/download/sdk.html

In a new or existing Scala Project create a new class called com.vff.HelloWorld – paste or type the following inside:

package com.vff

object HelloWorld extends App {
println("Hello, World!")
}

and now run this Scala class – in eclipse that means right-click, choose ‘Run As’ and then Scala Application from the available options. You should get ‘Hello, World!’ printed out in the console.

There are a few things of interest here. The use of ‘object’ for a class definition, the extending of ‘App’ and the simple ‘println’. Here goes..
‘object’ defines a class but defines it as a Singleton. only one instance will be created – it’s worth checking out Singleton if you don’t know it, basically one instance of this type is generated, no more instances can be created – a java equivalent might be a util class – all static methods. App is an existing scala type, extending it makes our class runnable. – like adding a big ‘public static void main(String[] args)’ around its contents. println is like a shortcut to System.out.println – nice and terse.

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