How do I kick-start my migration from Java to Scala?

Question

In Scala, what are the essential areas that beginners (in my case, I migrating from Java) has to learn to master the language?

Regardless of the method of learning (e.g., books, reading blogs, project euler) what order should one learn the essential aspects of Scala?

Answer 1

I've read the Programming Scala (O'Reilly), and now I'm reading Programming In Scala written by Martin Odersky.

I highly recommend to read the book by Martin Odersky, this book is WAY better than the other and give you a real sense of functionnal programming and a deep understanding of the language !

http://www.artima.com/shop/programming_in_scala_2ed

This is definitely the best way I found to dive into Scala !

Answer 2

The blog is fine. Another one with lessons for beginners is tony morris blog .

There are good introductory videos on parleys, on infoq and to be found on the main page from scala.

I would start with a mix - video is entertaining and makes hungry, take the short reference and online pdfs, as well as the blogs, and look for the '99 scala problems'. Try to solve problems, and reread your material if you get stuck.

Practice, practice, practice. Start small projects. Read here on SE, read blogs, the mailinglist. Get two or 3 books and study them in depth. Always: practise.

Update:

Since @Synesso got 3 up-votes for claiming, that Tony's blog isn't useful for beginners, I thought why this is a popular belief, and came to the opinion, that the older posts, more addressed towards beginners, need some popularisation, so I do you a favour and give precise links, and assert you, that I enjoyed them as a beginner. Now you're in the dilemma to believe me, or to think that I'm a genius. But sadly, I'm not. ;(

Here are

• scala exercises for beginners
• revised scala exercises
• intermediate exercises (yes, I admit, intermediate)
• further understanding scala Option
• 22 of 99
• scala-exercise (intermediate too)

Enjoy.

Answer 3

This is a good start: http://www.codecommit.com/blog/scala/scala-for-java-refugees-part-1

The author wrote 6 blog posts on the issue.

Answer 4

This is my favorite subject, as I too had a hard time getting into Scala. Do not get me wrong - I loved the language from the start - but there were so many parts to take in.

Remember that most software problems you encounter in the enterprise are not mathematical problems, therefore OO is what you should start out with to be able to do some damage in the organization.

To begin with you can safely skip the cool parts, like implicits and actors. What you really need for all everyday work is a deep understanding of the class, object, trait, apply(). To be able to work with immutable data you will need to understand the basics of functional programming, learn match and the for-yield construct.

Now you should learn SBT. I have found that this tool is essential, hope you learn to love it too.

Good luck!

Answer 5

If you come from Java the most important thing is to learn functional programming. Learning Haskell certainly helped me a lot cause it forces you to think in a functional way without resorting to old stateful habits. Real World Haskell is a quite good book to read.

Answer 6

I'm surprised nobody cited Odersky's stance on "what order to pick subjects to learn."

Answer 7

To master the language you have to learn how implicits work, plus all the different types and things like type constructors. Also, you'll need to bone up on persistent data structures, and some important functional concepts, like monads. Mmmmm. Basically, learn all of Scalaz, and you'll have some 80% of all of Scala. :-)

But from Java, that is the last thing you should do. You should first concentrate on what things are equivalent, what differences there are (for example, secondary constructors), and learn what functions are and how to use them.