Scala - Case class

// Case class

class Person(val _name: String, val _age: Int) {
  val name: String = _name
  val age: Int = _age
}

val p = new Person("Iraj", 30)
println(p)
println("====================")

// add toString

class Person2(val _name: String, val _age: Int) {
  val name: String = _name
  val age: Int = _age
  
  override def toString(): String = s"$name has $age year(s) old"
}

val p2 = new Person2("Iraj", 30)
println(p2)
println("====================")

// Update an object:
// 1. by defining properties as "var" (not so Scala style)
// 2. by making a copy of the object with new value

class Person3(val _name: String, val _age: Int) {
  val name: String = _name
  val age: Int = _age
  
  override def toString(): String = s"$name has $age year(s) old"
  
  def copy(newName: String): Person3 = new Person3(newName, age)
  def copy(newAge: Int): Person3 = new Person3(name, newAge)
  def copy(newName: String, newAge: Int) = new Person3(newName, newAge)
}

val p3 = new Person3("Iraj", 30)
println(p3)
println(p3.copy("John"))
println(p3.copy(40))
println(p3.copy("John", 40))
println("====================")


// Comparison
val p4 = new Person3("Iraj", 30)
println(s"Is '$p3' == '$p4': ${p3 == p4}")

class Person4(val _name: String, val _age: Int) {
  val name: String = _name
  val age: Int = _age
  
  override def toString(): String = s"$name has $age year(s) old"
  
  def copy(newName: String): Person3 = new Person3(newName, age)
  def copy(newAge: Int): Person3 = new Person3(name, newAge)
  def copy(newName: String, newAge: Int) = new Person3(newName, newAge)


  override def equals(that: Any): Boolean =
      this.name == that.asInstanceOf[Person4].name && 
      this.age == that.asInstanceOf[Person4].age

}

val p5 = new Person4("Iraj", 30)
val p6 = new Person4("Iraj", 30)
println(s"Is '$p5' == '$p6': ${p5 == p6}")

println("====================")

// All can be achieved by 
case class Person5(name: String, age: Int)

val p7 = new Person5("Iraj", 30)
val p8 = new Person5("Iraj", 30)
println(s"Is '$p7' == '$p8': ${p7 == p8}")