kotlin-stdlib/kotlin.collections/singleOrNull

singleOrNull

fun <T> Array<out T>.singleOrNull(): T?(source)
fun ByteArray.singleOrNull(): Byte?(source)
fun ShortArray.singleOrNull(): Short?(source)
fun IntArray.singleOrNull(): Int?(source)
fun LongArray.singleOrNull(): Long?(source)
fun FloatArray.singleOrNull(): Float?(source)
fun DoubleArray.singleOrNull(): Double?(source)
fun BooleanArray.singleOrNull(): Boolean?(source)
fun CharArray.singleOrNull(): Char?(source)

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?(source)
inline fun ByteArray.singleOrNull(predicate: (Byte) -> Boolean): Byte?(source)
inline fun ShortArray.singleOrNull(predicate: (Short) -> Boolean): Short?(source)
inline fun IntArray.singleOrNull(predicate: (Int) -> Boolean): Int?(source)
inline fun LongArray.singleOrNull(predicate: (Long) -> Boolean): Long?(source)
inline fun FloatArray.singleOrNull(predicate: (Float) -> Boolean): Float?(source)
inline fun DoubleArray.singleOrNull(predicate: (Double) -> Boolean): Double?(source)
inline fun BooleanArray.singleOrNull(predicate: (Boolean) -> Boolean): Boolean?(source)
inline fun CharArray.singleOrNull(predicate: (Char) -> Boolean): Char?(source)
inline fun <T> Iterable<T>.singleOrNull(predicate: (T) -> Boolean): T?(source)

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?(source)

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

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

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

@ExperimentalUnsignedTypes
fun UIntArray.singleOrNull(): UInt?(source)
@ExperimentalUnsignedTypes
fun ULongArray.singleOrNull(): ULong?(source)
@ExperimentalUnsignedTypes
fun UByteArray.singleOrNull(): UByte?(source)
@ExperimentalUnsignedTypes
fun UShortArray.singleOrNull(): UShort?(source)

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?(source)
@ExperimentalUnsignedTypes
inline fun ULongArray.singleOrNull(predicate: (ULong) -> Boolean): ULong?(source)
@ExperimentalUnsignedTypes
inline fun UByteArray.singleOrNull(predicate: (UByte) -> Boolean): UByte?(source)
@ExperimentalUnsignedTypes
inline fun UShortArray.singleOrNull(predicate: (UShort) -> Boolean): UShort?(source)

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