examples with simple Scala "bean" classes

classes_usage.scala

package examples.scala.php

object MainProve extends App {

  Predef println "Hello world!"

  val p1 = new Person1("John", "Doe")
  println(p1)

  val p2 = new Person2("John", "Doe")
  p2.age = 42
  println(p2)

  val p3 = new Person3()
  p3.firstName = "John"
  p3.lastName = "Doe"
  println(p3)

  try {
    p3.firstName = "NO"
  } catch {
    case e: Throwable => println("WARNING" + e.getMessage)
  }

}

case class Person1(firstName: String, lastName: String)

case class Person2(firstName: String, lastName: String) {

  private var my_age: Int = 0

  def age = this.my_age
  def age_=(a: Int) {
    require(a >= 0)
    this.my_age = a
  }
  override def toString() = s"Person[${firstName}, ${lastName}, ${age}]"

}

/*
 * Java Like example.
 */
class Person3 {

  private var first_name: String = null
  private var last_name: String = null
  private var my_age: Int = 0

  def firstName = first_name
  def firstName_=(name: String) = {
    require(name != null && name.length() >= 3)
    this.first_name = name
  }

  def lastName = last_name
  def lastName_=(name: String) = {
    require(name != null && name.length() >= 3)
    this.last_name = name
  }

  def age = this.my_age
  def age_=(a: Int) {
    require(a >= 0)
    this.my_age = a
  }

  override def toString() = s"Person[${firstName}, ${lastName}, ${my_age}]"

}