flatMap

Common
JVM
JS
Native
1.0
@JvmName ( "flatMapIterable" ) fun < T , R > Sequence < T > . flatMap (
transform : ( T ) -> Iterable < R >
) : Sequence < R >

(source)
fun < T , R > Sequence < T > . flatMap (
transform : ( T ) -> Sequence < R >
) : Sequence < R >

(source)

Returns a single sequence of all elements from results of transform function being invoked on each element of original sequence.

The operation is intermediate and stateless .

import kotlin.test.*

fun main(args: Array<String>) {
//sampleStart
val list = listOf("123", "45")
println(list.flatMap { it.toList() }) // [1, 2, 3, 4, 5]
//sampleEnd
}