Kotlin List takeLastWhile()
Syntax & Examples

Syntax of List.takeLastWhile()

The syntax of List.takeLastWhile() extension function is:

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

This takeLastWhile() extension function of List returns a list containing last elements satisfying the given predicate.

✐ Examples

1 Example

In this example,

We create a list named list1 containing the integers 10, 20, 30, 40, 50.
We apply takeLastWhile on list1 with the predicate { it > 25 }, which means to take elements from the list while they are greater than 25.
The result, which is a new list containing the elements 30, 40, 50, is stored in result.
Finally, we print the value of result to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list1 = listOf(10, 20, 30, 40, 50);
    val result = list1.takeLastWhile { it > 25 };
    print(result);
}

Output

[30, 40, 50]

2 Example

In this example,

We create a list named list1 containing the strings "apple", "banana", "grape", "orange".
We apply takeLastWhile on list1 with the predicate { it.length == 6 }, which means to take elements from the list from the trailing end while their length is 6.
The result, which is a new list containing the element "orange", is stored in result, because the while condition is broken for the element "grape".
Finally, we print the value of result to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list1 = listOf("apple", "banana", "grape", "orange");
    val result = list1.takeLastWhile { it.length == 6 };
    print(result);
}

Output

[orange]

Summary

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