none

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

Returns true if the array has no elements.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
assertTrue(emptyList.none())

val nonEmptyList = listOf("one", "two", "three")
assertFalse(nonEmptyList.none()) 
   //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

Returns true if no elements match the given predicate.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
assertFalse(zeroToTen.none { isEven(it) })
assertFalse(zeroToTen.none(isEven))

val odds = zeroToTen.map { it * 2 + 1 }
assertTrue(odds.none { isEven(it) })

val emptyList = emptyList<Int>()
assertTrue(emptyList.none { true }) 
   //sampleEnd
}

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

Returns true if the collection has no elements.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
assertTrue(emptyList.none())

val nonEmptyList = listOf("one", "two", "three")
assertFalse(nonEmptyList.none()) 
   //sampleEnd
}

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

Returns true if the map has no entries.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
assertTrue(emptyList.none())

val nonEmptyList = listOf("one", "two", "three")
assertFalse(nonEmptyList.none()) 
   //sampleEnd
}

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

Returns true if no entries match the given predicate.

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
assertFalse(zeroToTen.none { isEven(it) })
assertFalse(zeroToTen.none(isEven))

val odds = zeroToTen.map { it * 2 + 1 }
assertTrue(odds.none { isEven(it) })

val emptyList = emptyList<Int>()
assertTrue(emptyList.none { 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

Returns true if the array has no elements.

Since Kotlin

1.3

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val emptyList = emptyList<Int>()
assertTrue(emptyList.none())

val nonEmptyList = listOf("one", "two", "three")
assertFalse(nonEmptyList.none()) 
   //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

Returns true if no elements match the given predicate.

Since Kotlin

1.3

Samples

import samples.*
import kotlin.test.*
fun main() { 
   //sampleStart 
   val isEven: (Int) -> Boolean = { it % 2 == 0 }
val zeroToTen = 0..10
assertFalse(zeroToTen.none { isEven(it) })
assertFalse(zeroToTen.none(isEven))

val odds = zeroToTen.map { it * 2 + 1 }
assertTrue(odds.none { isEven(it) })

val emptyList = emptyList<Int>()
assertTrue(emptyList.none { true }) 
   //sampleEnd
}