Chapter2.scala

object Chapter2 {
  def main(args: Array[String]) {
    // declare functions
    def hello() = { "Hello World!" }
    println(hello)
    def hello2():String = { "Hello World2!" }
    println(hello2)
    def hello3 = "Hello World3!"
    println(hello3)

    def square (i:Int) = { i * i }
    println(square(3))

    def add(x: Int, y: Int): Int = { x + y }
    println(add(5, 6))

    // Arrays
    var books:Array[String] = new Array[String](3)
    books(1) = "hoge"
    for ( x <- books ) {
      println(x)
    }
    var books2 = Array("a", "b", "c")
    for ( x <- books2 ) {
      println(x)
    }

    // List
    var booklist: List[String] = List("Scala", "Groovy", "Java")
    println(booklist.head) // like car?
    println(booklist.tail) // like cdr?

    // Range
    println(1 to 5)
    println(1 until 5)
    println(1 to 20 by 4)

    // Tuple
    val tuple = (1, false, "Scala")
    println(tuple)
    println(tuple._1) // the first element has an index 1
    println(tuple._3)
    val tuple2 = "title" -> "Beginning Scala"
    println(tuple2)

    // If
    val ternary: Int = if (true) 1 else 3
    println(ternary)
    val ternary2: Int = if (false) 1
    else {
      val j = System.currentTimeMillis()
      (j % 100L).toInt
    }
    println(ternary2)
  }
}