Scala : Functional Java Programming - 2020

How Martin Odersky rewrote the rules of coding for a mobile world - Nov 28, 2012 from Gigaom

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Scala works with Java and compiles in the JVM, which is significant because many, many of the world's enterprise applications are written in Java. It's not a stretch to say there are millions of Java programmers (Oracle, which now owns Java, claims 9 million.) With Scala these programmers can keep using their Java libraries, frameworks and the JVM while also taking advantage of functional programming, which tends to be less verbose than Java code.
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Indeed.com's job post charts - the number of Scala job openings posted growing faster even than Ruby job postings late last year.

Scala is available @ Scala Distribution .

1. Martin Odersky's talk at OSCON 2011: Working Hard to Keep it Simple (slides)

2. Books:

   1. Structure and Interpretation of Computer Programs. Harold Abelson and Gerald J. Sussman. 2nd edition. MIT Press 1996. - [Full text available online].
   2. Programming in Scala. Martin Odersky, Lex Spoon and Bill Venners. 2nd edition. Artima 2010. - [Full text of 1st edition available online].

      Artima has graciously provided a 25% discount on the 2nd edition of Programming in Scala to all participants of this course. To receive the discount, simply visit http://www.artima.com/shop/programming_in_scala_2ed and during checkout, please use the coupon code: COURSERA-ODERSKY to have the discount applied.

   3. Scala for the Impatient. Cay Horstmann. Addison-Wesley 2012. - [First part available for download.]
   4. Scala in Depth. Joshua D. Suereth. Manning 2012. - [Available for purchase].
   5. Programming Scala. Dean Wampler and Alex Payne. O'Reilly 2008. [Online edition].

1. Scala Standard Library API
2. Scala School!: A Scala tutorial by Twitter
3. A Tour of Scala: Tutorial indroducing the main concepts of Scala
4. Scala Overview on StackOverflow: A list of useful questions sorted by topic

The Scala software distribution can be installed on any Unix-like or Windows system. It requires the Java runtime version 1.6 or later.

// HelloWorld.scala
object HelloWorld {
   def main(args: Array[String]) {
      println("Hello, world!")
   }
}

Compile:

$ scalac HelloWorld.scala

Run:

$ scala -classpath . HelloWorld
$ Hello, world!