maxWith

Returns the first element having the largest value according to the provided comparator.

@JvmName(name = "maxWithOrThrow")fun <T> Array<out T>.maxWith(comparator: Comparator<in T>): T(source)

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

val people = arrayOf(
    Person("Alice", 30),
    Person("Bob", 25),
    Person("Charlie", 35)
)

val oldest = people.maxWith(compareBy<Person> { it.age })

println("Oldest: ${oldest.name}, age ${oldest.age}")

Source