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.

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

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?

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

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.