kotlin-stdlib/kotlin.collections/singleOrNull

singleOrNull

fun <T> Array<out T>.singleOrNull(): T?

fun ByteArray.singleOrNull(): Byte?

fun ShortArray.singleOrNull(): Short?

fun IntArray.singleOrNull(): Int?

fun LongArray.singleOrNull(): Long?

fun FloatArray.singleOrNull(): Float?

fun DoubleArray.singleOrNull(): Double?

fun BooleanArray.singleOrNull(): Boolean?

fun CharArray.singleOrNull(): Char?

Returns single element, or null if the array is empty or has more than one element.

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

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

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

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

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

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

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

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

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

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

Returns the single element matching the given predicate, or null if element was not found or more than one element was found.

fun <T> Iterable<T>.singleOrNull(): T?

Returns single element, or null if the collection is empty or has more than one element.

fun <T> List<T>.singleOrNull(): T?

Returns single element, or null if the list is empty or has more than one element.

@ExperimentalUnsignedTypes

fun UIntArray.singleOrNull(): UInt?

@ExperimentalUnsignedTypes

fun ULongArray.singleOrNull(): ULong?

@ExperimentalUnsignedTypes

fun UByteArray.singleOrNull(): UByte?

@ExperimentalUnsignedTypes

fun UShortArray.singleOrNull(): UShort?

Returns single element, or null if the array is empty or has more than one element.

Since Kotlin

1.3

@ExperimentalUnsignedTypes

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

@ExperimentalUnsignedTypes

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

@ExperimentalUnsignedTypes

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

@ExperimentalUnsignedTypes

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

Returns the single element matching the given predicate, or null if element was not found or more than one element was found.

Since Kotlin

1.3