var map = scala.collection.mutable.Map("a" -> 1, "b"-> 2)

map("a")

map("a")=11

map + ("c"->3)

 map("d")
java.util.NoSuchElementException: key not found: d

map.get("d")
Option[Int] = None

map.getOrElse("d",0)
Int = 0

map - "a"



var map = Map("a" -> 1, "b"-> 2)
scala.collection.immutable.Map[String,Int] = Map(a -> 1, b -> 2)

map("a")=11
value update is not a member of scala.collection.immutable.

map = map + ("c"->3)

map = map - "a"

map.get("b")
Option[Int] = Some(2)