none

Начиная с Kotlin: 1.0

fun <T> Array<out T>.none(): Boolean

fun ByteArray.none(): Boolean

fun ShortArray.none(): Boolean

fun IntArray.none(): Boolean

fun LongArray.none(): Boolean

fun FloatArray.none(): Boolean

fun DoubleArray.none(): Boolean

fun BooleanArray.none(): Boolean

fun CharArray.none(): Boolean

Возвращает true, если массив пуст.

Примеры

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
println("emptyList.none() is ${emptyList.none()}") // true

val nonEmptyList = listOf("one", "two", "three")
println("nonEmptyList.none() is ${nonEmptyList.none()}") // false 
   //sampleEnd
}

inline fun <T> Array<out T>.none(predicate: (T) -> Boolean): Boolean

inline fun ByteArray.none(predicate: (Byte) -> Boolean): Boolean

inline fun ShortArray.none(predicate: (Short) -> Boolean): Boolean

inline fun IntArray.none(predicate: (Int) -> Boolean): Boolean

inline fun LongArray.none(predicate: (Long) -> Boolean): Boolean

inline fun FloatArray.none(predicate: (Float) -> Boolean): Boolean

inline fun DoubleArray.none(predicate: (Double) -> Boolean): Boolean

inline fun BooleanArray.none(predicate: (Boolean) -> Boolean): Boolean

inline fun CharArray.none(predicate: (Char) -> Boolean): Boolean

inline fun <T> Iterable<T>.none(predicate: (T) -> Boolean): Boolean

Возвращает true, если ни один элемент не соответствует заданному предикату.

Примеры

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
println("zeroToTen.none { isEven(it) } is ${zeroToTen.none { isEven(it) }}") // false
println("zeroToTen.none(isEven) is ${zeroToTen.none(isEven)}") // false

val odds = zeroToTen.map { it * 2 + 1 }
println("odds.none { isEven(it) } is ${odds.none { isEven(it) }}") // true

val emptyList = emptyList<Int>()
println("emptyList.none { true } is ${emptyList.none { true }}") // true 
   //sampleEnd
}

fun <T> Iterable<T>.none(): Boolean

Возвращает true, если коллекция пуста.

Примеры

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
println("emptyList.none() is ${emptyList.none()}") // true

val nonEmptyList = listOf("one", "two", "three")
println("nonEmptyList.none() is ${nonEmptyList.none()}") // false 
   //sampleEnd
}

fun <K, V> Map<out K, V>.none(): Boolean

Возвращает true, если карта пуста.

Примеры

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
println("emptyList.none() is ${emptyList.none()}") // true

val nonEmptyList = listOf("one", "two", "three")
println("nonEmptyList.none() is ${nonEmptyList.none()}") // false 
   //sampleEnd
}

inline fun <K, V> Map<out K, V>.none(predicate: (Map.Entry<K, V>) -> Boolean): Boolean

Возвращает true, если ни одна запись не соответствует заданному предикату.

Примеры

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
println("zeroToTen.none { isEven(it) } is ${zeroToTen.none { isEven(it) }}") // false
println("zeroToTen.none(isEven) is ${zeroToTen.none(isEven)}") // false

val odds = zeroToTen.map { it * 2 + 1 }
println("odds.none { isEven(it) } is ${odds.none { isEven(it) }}") // true

val emptyList = emptyList<Int>()
println("emptyList.none { true } is ${emptyList.none { true }}") // true 
   //sampleEnd
}


@ExperimentalUnsignedTypes
inline fun UIntArray.none(): Boolean


@ExperimentalUnsignedTypes
inline fun ULongArray.none(): Boolean


@ExperimentalUnsignedTypes
inline fun UByteArray.none(): Boolean


@ExperimentalUnsignedTypes
inline fun UShortArray.none(): Boolean

Возвращает true, если массив пуст.

Примеры

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
println("emptyList.none() is ${emptyList.none()}") // true

val nonEmptyList = listOf("one", "two", "three")
println("nonEmptyList.none() is ${nonEmptyList.none()}") // false 
   //sampleEnd
}


@ExperimentalUnsignedTypes
inline fun UIntArray.none(predicate: (UInt) -> Boolean): Boolean


@ExperimentalUnsignedTypes
inline fun ULongArray.none(predicate: (ULong) -> Boolean): Boolean


@ExperimentalUnsignedTypes
inline fun UByteArray.none(predicate: (UByte) -> Boolean): Boolean


@ExperimentalUnsignedTypes
inline fun UShortArray.none(predicate: (UShort) -> Boolean): Boolean

Возвращает true, если ни один элемент не соответствует заданному предикату.

Примеры

import kotlin.math.*
import kotlin.test.*

fun main() { 
   //sampleStart 
   val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
println("zeroToTen.none { isEven(it) } is ${zeroToTen.none { isEven(it) }}") // false
println("zeroToTen.none(isEven) is ${zeroToTen.none(isEven)}") // false

val odds = zeroToTen.map { it * 2 + 1 }
println("odds.none { isEven(it) } is ${odds.none { isEven(it) }}") // true

val emptyList = emptyList<Int>()
println("emptyList.none { true } is ${emptyList.none { true }}") // true 
   //sampleEnd
}

© 2010–2026 JetBrains s.r.o. and Kotlin Programming Language contributors
Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/core/kotlin-stdlib/kotlin.collections/none.html