DemoApplication.kt

package com.example.demo
import org.springframework.boot.autoconfigure.SpringBootApplication

@SpringBootApplication
class DemoApplication

fun main(args: Array<String>) {
    val p1 = Person("초기이름1", "초기성1")
    val p2 = Person("초기이름2", "초기성2")
    p1.firstName = "기완"
    p1.familyName = "맹"
    p1.age = 1
    p2.firstName = "현경"
    p2.familyName = "권"
    p2.age = 1
    p1.showMe()
    p2.showMe()
}
class Person(f: String, n: String){
    var firstName: String = f
    var familyName: String = n
    var age: Int = 0
    fun fullName() = "${this.firstName} $familyName"
    fun showMe() {
        println("${fullName()}: $age")
    }
    init{
        if(n.isEmpty() && " " in f){
            val s = f.split(" ")
            familyName = s[s.lastIndex]
            firstName = s.dropLast(1).joinToString(" ")
        }else{
            firstName = f
            familyName = n
        }
    }
}