kotlin-stdlib/kotlin.collections/lastOrNull

lastOrNull

fun <T> Array<out T>.lastOrNull(): T?(source)

fun ByteArray.lastOrNull(): Byte?(source)

fun ShortArray.lastOrNull(): Short?(source)

fun IntArray.lastOrNull(): Int?(source)

fun LongArray.lastOrNull(): Long?(source)

fun FloatArray.lastOrNull(): Float?(source)

fun DoubleArray.lastOrNull(): Double?(source)

fun BooleanArray.lastOrNull(): Boolean?(source)

fun CharArray.lastOrNull(): Char?(source)

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

Since Kotlin

1.0

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail

val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
   //sampleEnd
}
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val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail
val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
Open in Playground →
Target: JVMRunning on v.2.1.20

inline fun <T> Array<out T>.lastOrNull(predicate: (T) -> Boolean): T?(source)

inline fun ByteArray.lastOrNull(predicate: (Byte) -> Boolean): Byte?(source)

inline fun ShortArray.lastOrNull(predicate: (Short) -> Boolean): Short?(source)

inline fun IntArray.lastOrNull(predicate: (Int) -> Boolean): Int?(source)

inline fun LongArray.lastOrNull(predicate: (Long) -> Boolean): Long?(source)

inline fun FloatArray.lastOrNull(predicate: (Float) -> Boolean): Float?(source)

inline fun DoubleArray.lastOrNull(predicate: (Double) -> Boolean): Double?(source)

inline fun BooleanArray.lastOrNull(predicate: (Boolean) -> Boolean): Boolean?(source)

inline fun CharArray.lastOrNull(predicate: (Char) -> Boolean): Char?(source)

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

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

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

Since Kotlin

1.0

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail

val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
   //sampleEnd
}
xxxxxxxxxx
 
val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail
val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
Open in Playground →
Target: JVMRunning on v.2.1.20

fun <T> Iterable<T>.lastOrNull(): T?(source)

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

Since Kotlin

1.0

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail

val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
   //sampleEnd
}
xxxxxxxxxx
 
val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail
val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
Open in Playground →
Target: JVMRunning on v.2.1.20

fun <T> List<T>.lastOrNull(): T?(source)

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

Since Kotlin

1.0

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail

val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
   //sampleEnd
}
xxxxxxxxxx
 
val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail
val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
Open in Playground →
Target: JVMRunning on v.2.1.20

@ExperimentalUnsignedTypes

fun UIntArray.lastOrNull(): UInt?(source)

@ExperimentalUnsignedTypes

fun ULongArray.lastOrNull(): ULong?(source)

@ExperimentalUnsignedTypes

fun UByteArray.lastOrNull(): UByte?(source)

@ExperimentalUnsignedTypes

fun UShortArray.lastOrNull(): UShort?(source)

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

Since Kotlin

1.3

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail

val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
   //sampleEnd
}
xxxxxxxxxx
 
val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail
val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
Open in Playground →
Target: JVMRunning on v.2.1.20

@ExperimentalUnsignedTypes

inline fun UIntArray.lastOrNull(predicate: (UInt) -> Boolean): UInt?(source)

@ExperimentalUnsignedTypes

inline fun ULongArray.lastOrNull(predicate: (ULong) -> Boolean): ULong?(source)

@ExperimentalUnsignedTypes

inline fun UByteArray.lastOrNull(predicate: (UByte) -> Boolean): UByte?(source)

@ExperimentalUnsignedTypes

inline fun UShortArray.lastOrNull(predicate: (UShort) -> Boolean): UShort?(source)

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

Since Kotlin

1.3

Samples

import kotlin.test.*

fun main() { 
   //sampleStart 
   val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail

val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
   //sampleEnd
}
xxxxxxxxxx
 
val list = listOf(1, 2, 3, 4)
println(list.last()) // 4
println(list.last { it % 2 == 1 }) // 3
println(list.lastOrNull { it < 0 }) // null
// list.last { it < 0 } // will fail
val emptyList = emptyList<Int>()
println(emptyList.lastOrNull()) // null
// emptyList.last() // will fail 
Open in Playground →
Target: JVMRunning on v.2.1.20

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