kotlin-stdlib/kotlin.sequences/mapNotNull

mapNotNull

fun <T, R : Any> Sequence<T>.mapNotNull(transform: (T) -> R?): Sequence<R>(source)

Returns a sequence containing only the non-null results of applying the given transform function to each element in the original sequence.

The operation is intermediate and stateless.

Since Kotlin

1.0

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val strings: List<String> = listOf("12a", "45", "", "3")
val ints: List<Int> = strings.mapNotNull { it.toIntOrNull() }

println(ints) // [45, 3]
println(ints.sum()) // 48 
   //sampleEnd
}