Updating a Map

Add an entry without changing the original map.

MapUpdate.scala

object Main {
  def main(args: Array[String]): Unit = {
    val price = 
    val base = Map("a" -> 10, "b" -> 20)
    val updated = base + ("c" -> price)
    val found = updated.getOrElse("c", 0)

    println("baseSize=" + base.size)
    println("updatedSize=" + updated.size)
    println("c=" + found)
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val price = 
    val base = Map("a" -> 10, "b" -> 20)
    val updated = base + ("c" -> price)
    val found = updated.getOrElse("c", 0)

    println("baseSize=" + base.size)
    println("updatedSize=" + updated.size)
    println("c=" + found)
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val price = 
    val base = Map("a" -> 10, "b" -> 20)
    val updated = base + ("c" -> price)
    val found = updated.getOrElse("c", 0)

    println("baseSize=" + base.size)
    println("updatedSize=" + updated.size)
    println("c=" + found)
  }
}

map-update Adding a key with `+` returns a new map. The original map keeps its size, and a lookup on the new map reads the added value.