List Basics

Read simple facts from a small list.

ListBasics.scala

object Main {
  def main(args: Array[String]): Unit = {
    val extra = 
    val numbers = List(1, 2, 3)
    val extended = numbers :+ extra
    val first = extended.head
    val count = extended.length
    val joined = extended.mkString(",")

    println("first=" + first)
    println("count=" + count)
    println("joined=" + joined)
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val extra = 
    val numbers = List(1, 2, 3)
    val extended = numbers :+ extra
    val first = extended.head
    val count = extended.length
    val joined = extended.mkString(",")

    println("first=" + first)
    println("count=" + count)
    println("joined=" + joined)
  }
}

object Main {
  def main(args: Array[String]): Unit = {
    val extra = 
    val numbers = List(1, 2, 3)
    val extended = numbers :+ extra
    val first = extended.head
    val count = extended.length
    val joined = extended.mkString(",")

    println("first=" + first)
    println("count=" + count)
    println("joined=" + joined)
  }
}

list-basics A list stores values in order. You can count the values, read the first value, and build a display string.