kotlin类构造函数参数的默认值类型是什么？

class Person(name: String, age: Int = 18, gender: String = "Unknown") {
    // 类的属性
    var name: String = name
    var age: Int = age
    var gender: String = gender

    // 类的方法
    fun introduce() {
        println("My name is $name. I am $age years old. My gender is $gender.")
    }
}

fun main() {
    val person1 = Person("Alice")
    val person2 = Person("Bob", 25)
    val person3 = Person("Charlie", 30, "Male")

    person1.introduce() // 输出：My name is Alice. I am 18 years old. My gender is Unknown.
    person2.introduce() // 输出：My name is Bob. I am 25 years old. My gender is Unknown.
    person3.introduce() // 输出：My name is Charlie. I am 30 years old. My gender is Male.
}