Scala

1. Scala
Java++
https://www.youtube.com/watch?v=LH75sJAR0hc

2. Overview
Type Safe
Play Scala
Spark
Java
Martin Odersky

3. Language Design
Trait
Static(Infer) and Strongly Typed
Case Class
ActorHigh Order Function
Pattern Matcher
Optional

4. Hello World
s” Hello ${param}”

5. List/Dictionary
List(1, 2, 3) Map(“a” -> 1, “b” -> 2)

6. Set/Tuple
(“a”, “b”) Set(“a”, “b”, “c”)

7. Function/Lambda
s => println(s) callback: String => Unit

8. Closure
closure is like a class instance that has variables.

9. High-Order Function
map / filter / reduce

10. Class
a constructor is defined in a class block
cannot have class variables/methods

11. Object
is a singleton object. You cannot instantiate it.

12. Companion object
whose name is equivalent to the class in the same file
can access private parts.
usually designed to provide
factory methods.

13. Case Class
works like Enum.
generates a companion object automatically.
object Mobile()

14. Trait/Mix-in
Dependency Injection using Trait

15. Optional
Option(“David”) match Some() or None

16. Parallel
List.par