Kotlin Properties Getter/Setter

snippet.kt

// custom getter on an immutable property (no setter allowed)
class Person(val name: String, val birthday: LocalDate) {
  val age: Long
    get() = birthday.until(LocalDate.now(), ChronoUnit.YEARS)
}

// custom setter
class Contact {
  var firstName: String? = null
    set(value) {
      field = value?.capitalize()
    }
}

// private setter on a public property
class CharacterCounter {
  var count: Int = 0 
    private set
  
  fun add(str: String) = count += str.length
}