The randomOrNull() method is used to return a random element from the ArrayList. If the list is empty, then null is returned.
fun <T> Collection<T>.randomOrNull(): T?
This method doesn’t take any arguments.
This method returns a random element from the list if the list is not empty. Otherwise, it returns a null value.
The code given below demonstrates how we can use the randomOrNull() method:
fun main() {var list = ArrayList<Int>()list.add(1)list.add(2)list.add(3)println("The list is $list")var randElement = list.randomOrNull()println("Random element from the list ${randElement}")list = ArrayList<Int>();println("\nThe list is $list")randElement = list.randomOrNull()println("Random element from the list ${randElement}")}
Lines 3–6: We create a new ArrayList with the name list and add three elements to it, using the add method. The list is now [1,2,3].
Line 9: We use the randomOrNull method to get a random element from the list. This method returns a random element from the list.
Line 12: We assign an empty ArrayList as a value to the list variable.
Line 14: We use the randomOrNull method to get a random element from the list. This method returns a null value, because the list is empty.