ScalaNotes.md

Scala Notes

Tools Install for Linux

Install JDK

sudo apt-get install openjdk-8-jdk

Install sbt

Follow the installation instructions on http://www.scala-sbt.org/release/docs/Setup.html

echo "deb https://dl.bintray.com/sbt/debian /" | sudo tee -a /etc/apt/sources.list.d/sbt.list
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 2EE0EA64E40A89B84B2DF73499E82A75642AC823
sudo apt-get update
sudo apt-get install sbt

Test installation by running sbt about.

• To run REPL (Run - Evaluate - Print - Loop), furst run sbt than execute the console command. Finish REPL with Ctrl-D.
• To end sbt, use exit command or Ctrl-D.

IntelliJ IDEA

• Download from https://www.jetbrains.com/idea/download/ and unpack. See also [https://www.jetbrains.com/help/idea/2016.2/installing-and-launching.html#d1877341e227](Starting IntelliJ IDEA on Linux):

  mkdir apps
  cd apps
  tar xvzf ~/Downloads/ideaIC-2016.2.4.tar.gz
  cd idea-IC-162.2032.8/bin
  ./idea.sh
  

• Install Scala Plugin

• Select JVM as default VM

Basics

// Definition
def x = 3      //> x : => Int
def y = 7      //> y : => Int
def z = x * y  //> z : => Int
z              //> res0: Int = 21

// Definition can have parameters (function)
def increase(i: Int) = i + 1
// Function result type can be defined
def increase(i: Int):Int = i + 1

Primitive types

aa	bbb
Int	32 bit integer
Double	64 bit integer
Boolen	true or false

// Primitive

// Function can have multiple parameters and call other functions
def square(x: Double) = x * x
def sumOfSquares(x: Double, y: Double) = square(x) + square(y)