A n00bs guide to scala written by a n00b.

1. A quick introduction to:
BRANDON L. GULLA
CS722 - FALL 2014

2. History of Scala
 Founded in 2001 by Martin Odersky at the Ecole
Polytechnique Fédérale de Lausanne in France
(surprise).
 Wanted to create a language to solve functional
programming problems from the research/scientific
fields while maintaining the awesomeness that
comes with object-oriented programming
languages such as Java.
 Scala's codebase had roots in Martin's previous
work named Funnel.
 Martin was lazy* though...
*you'll get the pun later.

4. Java as a foundation.
 Odersky decided to create his new language on top
of the Java Virtual Machine.
 Scala is actually a library included in the Java
CLASSPATH.
 Martin decided to make the Scala language translate into
Java byte code, a instruction set that could be read on
everything from toasters to high-end enterprise work
stations.
 Confused?

5. Java Byte Code, Demystified

6. What's Scala look like? Hello World!
• Scala source code files are saved as ___.scala just like ___.java
• You compile scala with the scalac tool (included in the scala binary libraries)

7. But I like bells and whistles...
 Scala was born to solve functional problems that mathematicians
and Data-Scientists were facing.
 Just because the language is powerful for extremely nerdy
problems, it doesn't mean that it can't be pretty too!
 Since Scala shares the same VirtualMachine as Java, it can actually
use ANY Java package available, including GUI libraries such as
Swing!

8. JOptionPane in Scala

9. But Why Scala? Isn't Java awesome enough?
 No!
 Well, actually Java is pretty awesome, but you can extend that
awesomeness in Scala by using the same packages!
 Example: import apache.commons.io._
 Scala was created to meet the increasing scalability concerns of
distributed computing clusters.
 Big Data Big Data Big Data.

10. How is Scala Different?...
 Like languages such as SmallTalk and Objective-C, everything in Scala is
an object.
 There are no primitives in Scala (int, double, etc) but have been replaced
by Int, Double, Float, etc. Even operators (+,-) are objects and thus can be
re-defined!
 Lambda / Anonymous Functions:
 Scala allows you to create anonymous or Lambda functions. Lambda functions
are functional definitions that are not bound to an identifier. They are often
passed to another function as an argument. An example is below.
 You can actually pass a function as an argument parameter to another
function!

11. How is Scala Different?...
(continued)
 Reduced boilerplate. Map Reduce job in Java takes ~130 lines, but it
only takes 4 lines in Scala.
 val s = for (x <- 1 to 25 if x*x > 50) yield 2*x
 While everything is technically an object, Scala is a strictly-typed
programming language. This is a huge improvement over previously
used programming languages such as python and ruby.
 Scala code can be decompiled to readable Java code, with the
exception of certain constructor operations.
 The return operator is unnecessary in a function (although allowed);
the value of the last executed statement or expression is normally the
function's value.
 Polymorphism in Scala is identical to Java.

12. How is Scala Different?...
(continued some more )
 Functions do not need parenthesis to be called. Function or method
foo() can also be called as just foo and method foo.toString() can
also be called as just foo toString.
 Default visibility in Scala is ‘public’.
 It's fast.

13. Scala can be run in an interactive
shell!

14. Examples

15. Examples Continued

16. Future of Scala in Industry

17. Scala is the Hipster of Programming
Languages

18. • Who Uses Scala?

19. Questions?
****( I'm no expert, so be nice)
 Scala is open-sourced! Check it out on GitHub (github.com/scala)
 Check out books such as Scala for the Java Developer and Scala
for the Impatient.