第5章：型について語る ref: http://qiita.com/f81@github/items/f98e157210c0b83e5842

Car.java

public class Car {

    public static void main(String[] args) {
        final Car car = new Car("blue");
        car.run();
    }

    private static void output(String message) {
        System.out.println(message);
    }

    private final String color;

    public Car(String color) {
        this.color = color;
    }

    public String getColor() {
        return color;
    }

    public void run() {
        output("Start!!!");
    }
}

Car.scala

object Car {
  def main(args: Array[String]){
    var car = new Car("blue")
    car.run
  }

  private def output(message: String):Unit=println(message)
}

class Car(color: String) {
  def run = {
    Car.output("Start!!!")
  }
}

CarExtends.scala

object CarExtends {
  def main(args: Array[String]){
    var car = new Car("blue")
    output(car)
    car.run

    var truck = new Truck("Silver")
    output(truck)
    truck.run
  }

  def output(car: Car):Unit=println("Color is " + car.color + ".")
}

class Car(val color: String) {
  def run = println("Start!!!")
}

class Truck(color: String) extends Car(color) {
  override def run =println("Truck start!!!")
}

file0.txt

$ scala
Welcome to Scala version 2.10.1 (Java HotSpot(TM) 64-Bit Server VM, Java 1.7.0_25).
Type in expressions to have them evaluated.
Type :help for more information.

scala>

file1.txt

scala> val i = 1
i: Int = 1

file10.txt

def output(car: Car):Unit=println("Color is " + car.color + ".")

file11.txt

var car = new Car("blue")
output(car)

file12.txt

var truck = new Truck("Silver")
output(truck)

file2.txt

scala> val d = 1.5
d: Double = 1.5

file3.txt

scala> val s = "雷電"
s: String = "雷電"

file5.txt

$ scalac Car.scala

$ scala Car
Start!!!

file7.txt

def run = {
  Car.output("Start!!!")
}

file9.txt

$ scalac CarExtends.scala

$ scala CarExtends
Color is blue.
Start!!!
Color is Silver.
Truck start!!!