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class Person(val name: String, val age: Int, val weight: Int)
object Person {
def apply(name: String, age: Int, weight: Int): Person = new Person(name, age, weight)
def unapply(arg: Person): Option[(String, Int, Int)] =
if(arg.age >= 20) Some(arg.name, arg.age, arg.weight)
else None
}
val young: Person = Person("Martin Junior", 14, 50)
val old: Person = Person("Martin", 29, 70)
def PatternMatching(person: Person): Unit = person match {
case Person(name, age, weight) => println(s"name: $name, age: $age, weight: $weight")
case _ => println(s"${person.name} is under 20")
}
PatternMatching(young)
PatternMatching(old)
class SecretPerson(val name: String, val age: Int, val weight: Int)
object SecretPerson {
def apply(name: String, age: Int, weight: Int): SecretPerson = new SecretPerson(name, age, weight)
def unapply(arg: SecretPerson): Option[(String, Int)] =
if(arg.age >= 20) Some(arg.name, arg.age)
else None
}
def PatternMatchingSecret(secretPerson: SecretPerson): Unit = secretPerson match {
case SecretPerson(name, age) => println(s"name: $name, age: $age")
case _ => println(s"${secretPerson.name} is under 20")
}
val secretYoung: SecretPerson = SecretPerson("Martin Junior", 14, 50)
val secretOld: SecretPerson = SecretPerson("Martin", 29, 70)
PatternMatchingSecret(secretYoung)
PatternMatchingSecret(secretOld)
case class CasePerson(name: String, age: Int, weight: Int)
object CasePerson {
// Compile Error - unapply is defined twice
// def unapply(arg: CasePerson): Option[(String, Int)] =
// if(arg.age >= 20) Some(arg.name, arg.age)
// else None
}
val caseYoung: CasePerson = CasePerson("Martin Junior", 14, 50)
val caseOld: CasePerson = CasePerson("Martin", 29, 70)
def PatternMatchingCase(casePerson: CasePerson): Unit = casePerson match {
// case CasePerson(name, age) => println(s"name: $name, age: $age") compile error: wrong number of arguments
case CasePerson(name, age, weight) => println(s"name: $name, age: $age, weight: $weight")
case _ => println(s"${casePerson.name} is under 20")
}
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