Re: Two new functions array_first() and array_last()

On Tue, Oct 17, 2023 at 11:22 AM Lynn <kjarli@gmail.com> wrote: > > > > On Tue, Oct 17, 2023 at 11:15 AM Robert Landers <landers.robert@gmail.com> wrote: >> >> On Tue, Oct 17, 2023 at 11:10 AM Levi Morrison via internals >> <internals@lists.php.net> wrote: >> >> How is returning null any different than $array[0] on an empty array? >> https://3v4l.org/> > > > > c) Two such functions were proposed and rejected during the > > > array_key_first/last RFC > > > (https://wiki.php.net/rfc/array_key_first_last) > > > > > > Yes, that was in 2018. At that time, functions like str_contains() or > > > str_starts_with() wouldn't have even come into existence, just because > > > there was an obscure way to do it without them. I believe we've moved > > > on since then. Today we know how useful it is to use simple, > > > easy-to-understand methods, both for programmers who write and read > > > the code. > > > > It's true that sentiment may have shifted in this time. However, a > > common argument at that time still stands: null is not a > > good > > sentintenal for failure because the value inside the array very well > > could have been null. This is not true for the keys. For me > > personally, I think I would still vote no. I'm not entirely sure about > > that, but that's how I would lean right now. > > > > As it stands, you'd have to write code along the lines of: > > > > ```php > > $key = \array_key_first($array); > > if ($key === null) { > > // handle the failure > > } else { > > // success > > $value = $array[$key]; > > } > > ``` > > > > Yes, it would be slightly nicer if we could do: > > > > ```php > > $value = \array_first($array); > > if ($value === null) { > > // handle the failure > > } else { > > // success > > } > > ``` > > > > But I fear in practice people will just omit the error checking. > > > > One way around that is to throw an exception. I'm not sure how I feel > > about that, but I'll think about it. > > > > -- > > PHP Internals - PHP Runtime Development Mailing List > > To unsubscribe, visit: https://www.php.net/unsub.php >> >> >K3gRs >> >> Currently, it just outputs a warning, but the result is >> null. >> >> -- >> PHP Internals - PHP Runtime Development Mailing List >> To unsubscribe, visit: https://www.php.net/unsub.php >> > > I'm okay with null being given back as it's the > current behavior of accessing the key as well, which is often checked through > $array[0] ?? null. Something like an > undefined type could solve this problem, but personally not a fan of > this in Javascript. Maybe array_has_first or something could be > made, but honestly I would still just check for null myself most > likely. Huh, that's a good observation Lynn. If I might suggest an API change to array_value_first (and a similar one for array_value_last), it would be this: `array_value_first(array $array, string|int|null &$key = null): mixed` where you also get back the key. If you want to know if null is an error or an actual value: $value = array_value_first($array, $key); if($key === null) // handle error else // do something with $value You can also freely ignore the key, if you don't need it or care about error checking. That would save doing two function calls on the same array, just to do some error checking.