kotlin-stdlib/kotlin.comparisons/nullsLast

nullsLast

fun <T : Any> nullsLast(comparator: Comparator<in T>): Comparator<T?>

Extends the given comparator of non-nullable values to a comparator of nullable values considering null value greater than any other value.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val list = listOf(4, null, 1, -2, 3)

val nullsFirstList = list.sortedWith(nullsFirst(reverseOrder()))
assertPrints(nullsFirstList, "[null, 4, 3, 1, -2]")

val nullsLastList = list.sortedWith(nullsLast(reverseOrder()))
assertPrints(nullsLastList, "[4, 3, 1, -2, null]") 
   //sampleEnd
}

inline fun <T : Comparable<T>> nullsLast(): Comparator<T?>

Provides a comparator of nullable Comparable values considering null value greater than any other value.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val list = listOf(4, null, -1, 1)

val nullsFirstList = list.sortedWith(nullsFirst())
assertPrints(nullsFirstList, "[null, -1, 1, 4]")

val nullsLastList = list.sortedWith(nullsLast())
assertPrints(nullsLastList, "[-1, 1, 4, null]") 
   //sampleEnd
}