kotlin-stdlib/kotlin.collections/associateWith

associateWith

inline fun <K, V> Iterable<K>.associateWith(valueSelector: (K) -> V): Map<K, V>(source)

Returns a Map where keys are elements from the given collection and values are produced by the valueSelector function applied to each element.

If any two elements are equal, the last one gets added to the map.

The returned map preserves the entry iteration order of the original collection.

Since Kotlin

1.3

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val words = listOf("a", "abc", "ab", "def", "abcd")
val withLength = words.associateWith { it.length }
println(withLength.keys) // [a, abc, ab, def, abcd]
println(withLength.values) // [1, 3, 2, 3, 4] 
   //sampleEnd
}