按kotlin中子元素列表值对列表进行分组

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

fun main() {
    val people = listOf(
        Person("Alice", 20),
        Person("Bob", 25),
        Person("Charlie", 20),
        Person("Dave", 25)
    )

    val groupedPeople = people.groupBy { it.age }

    for ((age, group) in groupedPeople) {
        println("Age: $age")
        for (person in group) {
            println("- ${person.name}")
        }
    }
}

Age: 20
- Alice
- Charlie
Age: 25
- Bob
- Dave