kotlin-stdlib/kotlin.sequences/lastOrNull

lastOrNull

Returns the last element, or null if the sequence is empty.

The operation is terminal.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
assertPrints(list.last(), "4")
assertPrints(list.last { it % 2 == 1 }, "3")
assertPrints(list.lastOrNull { it < 0 }, "null")
assertFails { list.last { it < 0 } }

val emptyList = emptyList<Int>()
assertPrints(emptyList.lastOrNull(), "null")
assertFails { emptyList.last() } 
   //sampleEnd
}

inline fun <T> Sequence<T>.lastOrNull(predicate: (T) -> Boolean): T?

Returns the last element matching the given predicate, or null if no such element was found.

The operation is terminal.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
assertPrints(list.last(), "4")
assertPrints(list.last { it % 2 == 1 }, "3")
assertPrints(list.lastOrNull { it < 0 }, "null")
assertFails { list.last { it < 0 } }

val emptyList = emptyList<Int>()
assertPrints(emptyList.lastOrNull(), "null")
assertFails { emptyList.last() } 
   //sampleEnd
}