What's the difference between `find { }` and `firstOrNull { }` on `Iterable<T>` in the stdlib?

# announcements

[dave08]

What's the difference between find { } and firstOrNull { } on Iterable<T> in the stdlib?

[gsala]

There isn't a difference (https://youtrack.jetbrains.com/issue/KT-5185)

[Anton Lakotka [JB]]

From source code:

/**
 * Returns the first element matching the given [predicate], or `null` if no such element was found.
 */
@kotlin.internal.InlineOnly
public inline fun <T> Iterable<T>.find(predicate: (T) -> Boolean): T? {
    return firstOrNull(predicate)
}

[Anton Lakotka [JB]]

hence find is just an alias

[dave08]

Interesting discussion over there... so most people would use find?

[Anton Lakotka [JB]]

it depends. find is shorter, but in some cases firstOrNull may be more "expressive" in terms of readability.

[Anton Lakotka [JB]]

for example from code context you are dealing with list of unique elements then it makes sense to use find.
in case of list which may have duplicates firstOrNull now makes more sense.

[dave08]

That's why I was expecting Set<T>.find... I was surprised it was on Iterable. Thanks for the confirmation 🙂!