lastOrNull
Returns the last character, or null if the char sequence is empty.
fun CharSequence.lastOrNull(): Char?(source)
fun main() {
val text = "Kotlin"
val lastChar: Char? = text.lastOrNull()
println(lastChar) // prints 'n'
val empty = ""
val lastEmpty: Char? = empty.lastOrNull()
println(lastEmpty) // prints 'null'
}