groupBy Kotlin中的多个字段和sum值

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

fun main() {
    val people = listOf(
        Person("Alice", 25, 50000.0),
        Person("Bob", 30, 60000.0),
        Person("Charlie", 25, 55000.0),
        Person("Dave", 30, 65000.0)
    )

    val groupedPeople = people.groupBy { it.age }
    val sumOfSalaries = people.sumByDouble { it.salary }

    println("Grouped People: $groupedPeople")
    println("Sum of Salaries: $sumOfSalaries")
}

Grouped People: {25=[Person(name=Alice, age=25, salary=50000.0), Person(name=Charlie, age=25, salary=55000.0)], 30=[Person(name=Bob, age=30, salary=60000.0), Person(name=Dave, age=30, salary=65000.0)]}
Sum of Salaries: 230000.0