scala/ScalaBook/chapter-02/map.scala

import scala.collection.mutable.HashMap

var colors = Map("red"   ->  "#FF0000",
                 "azure" ->  "#F0FFFF",
                 "peru"  ->  "#CD853F")
var tmp_colors = colors
colors += ("indigo" -> "#4B0082")
println(colors.size)

if (colors.equals(tmp_colors)) 
   println("colors and tmp_colors are equal")
else
   println("colors and tmp_colors are not equal")

if (colors == tmp_colors) 
   println("colors and tmp_colors are equal")
else
   println("colors and tmp_colors are not equal")

if (!colors.contains("green")) 
  println("Error: \"green\"  is not defined!\n")

colors -= "azure" 

if (!colors.contains("azure")) 
  println("Pair for \"azure\"  has been removed.\n")

colors.foreach( c => colors -= c._1)
if (colors.isEmpty) println("empty")

var letters: Map[Char,Int] = Map()
val word = "Πρόεδρος"
word.foreach( l => letters += (l -> l.toInt) )

var sum = 0
letters.values.foreach(v => sum += v)
println(sum)

letters.elements.foreach(println)


val keys = Array(1, 2, 3)
val values = Array("A", "B", "C")
val map = Map(keys.zip(values) : _*)
map.elements.foreach(println)