lastOrNull
Returns the last element, or null if the progression is empty.
fun IntProgression.lastOrNull(): Int?(source)
fun main() {
val ascending = 1..5
println(ascending.lastOrNull()) // prints 5
val descending = 5 downTo 1
println(descending.lastOrNull()) // prints 1
val empty = 5..0
println(empty.lastOrNull()) // prints null
}