kotlin-stdlib / kotlin.sequences / filterIndexed

filterIndexed

Common
JVM
JS
Native
1.0
fun <T> Sequence<T>.filterIndexed(
    predicate: (index: Int, T) -> Boolean
): Sequence<T>
(source)

Returns a sequence containing only elements matching the given predicate.

import kotlin.test.*

fun main(args: Array<String>) {
//sampleStart
val numbers: List<Int> = listOf(0, 1, 2, 3, 4, 8, 6)
val numbersOnSameIndexAsValue = numbers.filterIndexed { index, i -> index == i }

println(numbersOnSameIndexAsValue) // [0, 1, 2, 3, 4, 6]
//sampleEnd
}

Parameters

predicate -

function that takes the index of an element and the element itself and returns the result of predicate evaluation on the element.

The operation is intermediate and stateless.