Kotlin List lastOrNull()
Syntax & Examples

Syntax of List.lastOrNull()

There are 2 variations for the syntax of List.lastOrNull() extension function. They are:

fun <T> List<T>.lastOrNull(): T?

This extension function returns the last element, or null if the list is empty.

fun <T> List<T>.lastOrNull(predicate: (T) -> Boolean): T?

This extension function returns the last element matching the given predicate, or null if no such element was found.

✐ Examples

1 Example

In this example,

We create a list named list containing strings 'apple', 'banana', 'orange'.
We use the lastOrNull() function to retrieve the last element of list.
Since the list is not empty, the last element is returned.
Finally, we print the last element to standard output.

Kotlin Program

fun main(args: Array<String>) {
    val list = listOf("apple", "banana", "orange");
    val lastElement = list.lastOrNull();
    println("Last element: \$lastElement");
}

Output

Last element: orange

2 Example

In this example,

We create a list named list containing characters 'a', 'b', 'c'.
We use the lastOrNull() function to retrieve the last element of list.
Since the list is not empty, the last element is returned.
Finally, we print the last element to standard output.

Kotlin Program

fun main(args: Array<String>) {
    val list = listOf('a', 'b', 'c');
    val lastElement = list.lastOrNull();
    println("Last element: \$lastElement");
}

Output

Last element: c

3 Example

In this example,

We create a list named list containing strings 'one', 'two', 'three'.
We use the lastOrNull() function with a predicate to find the last element with a length greater than 10.
Since there is no element in the list with a length greater than 10, null is returned.
Finally, we print the result to standard output.

Kotlin Program

fun main(args: Array<String>) {
    val list = listOf("one", "two", "three");
    val lastElement = list.lastOrNull { it.length > 10 };
    println("Last element with length greater than 10: \$lastElement");
}

Output

Last element with length greater than 10: null

Summary

In this Kotlin tutorial, we learned about lastOrNull() extension function of List: the syntax and few working examples with output and detailed explanation for each example.