Chapter3続き.scala

package chapter3.inheritance

/**
  * Created by hoshi on 1/14/16.
  */
class Vehicle(speed: Int) {
  val mph: Int = speed

  def race() = println("Racing MPH:" + speed)
}

/*
 * Method overriding requires the "override" keyword
 * Only the primary constructor can pass parameters to the base constructor
 */
class Car(speed: Int) extends Vehicle(speed) {
  override val mph: Int = speed

  override def race() = println("Racing Car MPH:" + mph)
}

class Bike(speed: Int) extends Vehicle(speed) {
  override val mph: Int = speed

  override def race() = println("Racing Bike MPH:" + mph)
}

trait flying {
  def fly() = println("flying")
}

trait gliding {
  def gliding() = println("gliding")
}

class Batmobile(speed: Int) extends Vehicle(speed) with flying with gliding {
  override def race() = println("Racing Batmobile MPH:" + mph)

  override def fly() = println("Flying Batmobile")
}

object VehicleMain extends App {
  val v1 = new Car(200)
  v1.race()
  val v2 = new Bike(100)
  v2.race()

  val v3 = new Batmobile(300)
  v3.race()
  v3.fly()
  v3.gliding()

  // Using maxBy
  val vList = List(v1, v2, v3)
  val fastest = vList.maxBy(_.mph)
  fastest.race()
}

----

package chapter3.inheritance

/**
  * Created by hoshi on 1/14/16.
  * case class provides toString, hashCode, and equals
  */
case class Stuff(name: String, age: Int)

object CaseClassMain {
  def main(args: Array[String]) {
    val s = new Stuff("David", 45)
    println(s)
    println(s == Stuff("David", 45))
    println(s == Stuff("David", 43))
    println(s.name)
    println(s.age)
  }
}

----

package chapter3.inheritance

/**
  * Created by hoshi on 1/14/16.
  */
class ValueClass(val i: Int) extends AnyVal {
  def twice() = i * 2
}

object ValueClassMain extends App {
  def with42(in: Int => Int) = in(42)

  val v = new ValueClass(9)
  println(v.twice())

  //etc (legal in Scala)
  println(1.hashCode())
  println(2.toString)
  // give a unction
  println(with42(33 +))
}