OO Hello World - Scala

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Update 1: Porting code examples to Scala 2.10.1 - support for String Interpolation.

The Hello World in Scala, the "scalable language" is here!

Scala is a very powerful multi-paradigm (OO and Functional) language. It targets the Java JVM and can easily interoperate with existing Java code. Its syntax is kind of Java-Like as well as Groovy and other languages.


By the way, you can see my previous post here: http://carlosqt.blogspot.com/2010/06/oo-hello-world.html
where I give some details on WHY these "OO Hello World series" samples.

Version 1 (Minimal):

The minimum you need to type to get your program compiled and running.

class Greet(name: String) {
    var _name: String = name.capitalize
    def salute() = println(s"Hello ${_name}!")
}

object Program {
    def main(args: Array[String]) = {
        val g = new Greet("world")
        g.salute
    }
}

Version 2 (Verbose):

Explicitly adding instructions and keywords that are optional to the compiler.

package com.series
import scala._  

class Greet(name: String) {
    private var _name: String = { name.capitalize }  
    def salute() = { println(s"Hello ${_name}!") }
}

object Program {
    def main(args: Array[String]): Unit = {
        val g = new Greet("world")                
        g.salute
    }
}

The Program Output:

Scala Info:

“Scala is a general purpose programming language designed to express common programming patterns in a concise, elegant, and type-safe way. It smoothly integrates features of object-oriented and functional languages, enabling Java and other programmers to be more productive. Code sizes are typically reduced by a factor of two to three when compared to an equivalent Java application.” Taken from: (http://www.scala-lang.org/node/25)

Appeared:	2003
Current Version:	2.8.1 RC4  (latest version in "Languages" page)
Developed by:	Martin Odersky
Creator:	Martin Odersky
Influenced by:	Java (James Gosling)
Predecessor Language	Funnel?
Predecessor Appeared	1999
Predecessor Creator	Martin Odersky
Runtime Target:	JVM
Latest Framework Target:	JDK 6
Mono Target:	No
Allows Unmanaged Code:	No
Source Code Extension:	“.scala”
Keywords:	40
Case Sensitive:	Yes
Free Version Available:	Yes
Open Source:	Yes
Standard:	No
Latest IDE Support:	NetBeans 6.9 http://netbeans.org/downloads/index.html Eclipse http://www.eclipse.org/downloads/ IntelliJ IDEA http://www.jetbrains.com/idea/download/index.html
Language Reference:	http://www.scala-lang.org/docu/files/ScalaReference.pdf
Extra Info:	http://en.wikipedia.org/wiki/Scala_(programming_language) http://www.scala-lang.org/node/197