kotlin-stdlib / kotlin.sequences / filterIndexedTo

filterIndexedTo

Common
JVM
JS
Native
1.0
inline fun <T, C : MutableCollection<in T>> Sequence<T>.filterIndexedTo(
    destination: C,
    predicate: (index: Int, T) -> Boolean
): C
(source)

Appends all elements matching the given predicate to the given destination.

import kotlin.test.*

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

println(numbersOnSameIndexAsValue) // []

numbers.filterIndexedTo(numbersOnSameIndexAsValue) { 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 terminal.