如何在Scala上使用属性？

class Person(val name: String, var age: Int)

val person = new Person("Alice", 30)
println(person.name) // 输出 "Alice"
println(person.age) // 输出 30

person.age = 31
println(person.age) // 输出 31

class Person(val name: String, var age: Int) {
  def getAge: Int = age
  def setAge(newAge: Int): Unit = age = newAge
}

val person = new Person("Alice", 30)
println(person.getAge) // 输出 30
person.setAge(31)
println(person.getAge) // 输出 31