maxBy

Returns the first element yielding the largest value of the given selector function.

@JvmName(name = "maxByOrThrow")inline fun <T, R : Comparable<R>> Array<out T>.maxBy(selector: (T) -> R): T(source)

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

val people = arrayOf(
    Person("Alice", 28),
    Person("Bob", 35),
    Person("Charlie", 22)
)

val oldest = people.maxBy { it.age }
println(oldest.name)   // Bob

Source