Kotlin List dropLastWhile()
Syntax & Examples

Syntax of List.dropLastWhile()

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

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

This dropLastWhile() extension function of List returns a list containing all elements except last elements that satisfy the given predicate.

✐ Examples

1 Example

In this example,

We create a list of integers list.
We use the dropLastWhile function with a predicate to drop elements greater than 3.
The resulting list result contains elements 1, 2, 3.
Finally, we print the result list to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list = listOf(1, 2, 3, 4, 5, 6)
    val result = list.dropLastWhile { it > 3 }
    print(result)
}

Output

[1, 2, 3]

2 Example

In this example,

We create a list of characters list.
We use the dropLastWhile function with a predicate to drop elements until we encounter 'c'.
The resulting list result contains elements a, b.
Finally, we print the result list to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list = listOf(&quot;a&quot;, &quot;b&quot;, &quot;c&quot;, &quot;d&quot;)
    val result = list.dropLastWhile { it != &quot;c&quot; }
    print(result)
}

Output

[a, b, c]

3 Example

In this example,

We create a list of strings list.
We use the dropLastWhile function with a predicate to drop elements with length greater than 5.
The resulting list result contains elements apple, banana.
Finally, we print the result list to standard output using print statement.

Kotlin Program

fun main(args: Array<String>) {
    val list = listOf(&quot;apple&quot;, &quot;banana&quot;, &quot;mango&quot;, &quot;avocado&quot;)
    val result = list.dropLastWhile { it.length > 5 }
    print(result)
}

Output

[apple, banana, mango]

Summary

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