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singleOrNull

Platform and version requirements: JVM (1.0), JS (1.0), Native (1.0)
fun <T> Sequence<T>.singleOrNull(): T?

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

The operation is terminal.

Platform and version requirements: JVM (1.0), JS (1.0), Native (1.0)
inline fun <T> Sequence<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.

The operation is terminal.

© 2010–2020 JetBrains s.r.o. and Kotlin Programming Language contributors
Licensed under the Apache License, Version 2.0.
https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.sequences/single-or-null.html