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

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