Vals and Vars

Use a fixed value and a changing variable in one small calculation.

ValsVars.scala

object Main {
  def main(args: Array[String]): Unit = {
    val base = 
    var running = base
    running = running + 2
    val finalValue = running

    println("base=" + base)
    println("final=" + finalValue)
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val base = 
    var running = base
    running = running + 2
    val finalValue = running

    println("base=" + base)
    println("final=" + finalValue)
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val base = 
    var running = base
    running = running + 2
    val finalValue = running

    println("base=" + base)
    println("final=" + finalValue)
  }
}

vals-vars A `val` is assigned once. A `var` can be reassigned when a step needs changing state.