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

Le 15/10/2023 à 01:11, Ben Ramsey a écrit :

On Oct 14, 2023, at 16:30, Nikita Popov <nikita.ppv@gmail.com> wrote: On Sat, Oct 14, 2023, at 20:00, David Grudl wrote:

PHP lacks two very basic functions for working with arrays: - array_first() returning the first element of an array (or null) - array_last() returning the last element of the array (or null) While PHP has functions that return the first and last keys, array_key_first() and array_key_last(), it does not have more useful functions for values. a) What about reset() and end()? Programmers "abuse" the reset() and end() functions for this purpose. The problem is that these functions are used to move the internal pointer in the array. Which is why they have a name that is inappropriate when used in the sense of "return me the first element". Much worse, they shouldn't to be used to get first/last value, because they have a side effect (i.e. moving the pointer). Further, in the absence of an element, they return the obsolete false and not the currently expected null, which can be combined with the ?? operator. In this they differ from the similar functions array_key_first() and array_key_last(). b) What about $array[array_key_first($array)]? For such basic functions as returning the first and last item in an array, there should be a function in the basic package, not a workaround. Moreover, this requires having the array in a local variable, since $this->getFoo()[array_key_first($this->getFoo())] would be very inefficient and possibly incorrect. 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. DG

I'm in favor of adding these. To add to what you already said, because reset/end modify the array, there's a good chance that calling these functions will copy the whole array due to a modification you are not actually interested in. So basically you have the choice between calling end(), which is the wrong thing to do semantically and may be slow, or using $array[array_key_last($array)], which is rather convoluted, and incorrect if the array is potentially empty. Regards, Nikita

I’m in favor of these functions, for all the same aforementioned reasons.

Yes please ! array_first() and array_last() are definitely needed. I wrote `foreach ($foo as $value) break;` too many times in my life. array_key_first() and array_key_last() I wouldn't use it much, but they'd probably  find their use cases as well. The first two probably only make sense for a numerically indexed array, so I guess that array_is_list() (whatever the name is, I don't want to bikeshed about naming) would be a good addition as well, that, in my opinion, would be pertinent to add at the same time. Regards, Pierre