Re: [Pre-RFC] Null coalescing associative array elements

On Fri, May 29, 2026, at 4:31 AM, Alexander Egorov wrote: > Greetings, internals! > > In my practice, it is a very common case when I need to create an > associative array with varying structure, by that meaning that some > fields in the array are optional and are set conditionally. And of all > conditions the most frequent is checking for null-values: if the value > is null, then this field should be omitted from the final result. > > Unfortunately, PHP currently does not offer any shorthand syntax for > declaring such fields in a compact way. In most cases for each of such fields > we need to have a dedicated "if", like: > > // $array is first filled with all required fields > // Then we add all optional fields based on some condition > if ($value !== null) { > $array['field'] = $value; > } > > This often leads to cumbersome code. > > My proposal, which already has a prototype implementation, is following. > When declaring an associative array, add a new null-coalescing double > arrow for the fields which should be omitted if the value is null: > > $array = [ > 'field1' => $param1, > 'field2' => $param2, > 'field3' ?=> $param3, > ]; > > In this case, if $param3 === null, the created array would only > contain 'field1' and 'field2' from start, without the need to later > get rid of 'field3'. > > This syntax will also allow more generalized conditions. For example, > instead of: > > if ($someCondition) { > $array['field'] = $value; > } > > You could create such array from start, if you are OK with such code-style: > > $array = [ > // other fields > 'field' ?=> $someCondition ? $value : null, > ]; > > The token '?=>' given here is mainly just an example, because the > exact form should be discussed anyway (this one, as well as others, > have pros and cons). > > So, before I create an RFC for this feature, I would like to get > initial feedback: would this feature be welcome in general? > > Prototype implementation for it: > > https://github.com/Amegatron/php-src/tree/conditional-array-elements > > Or just the diff with current master: > > https://github.com/php/php-src/compare/master...Amegatron:php-src:conditional-array-elements > > This is still a prototype though, some additional work must be done of > course, not counting the tests. > > A slightly bigger example: > > https://gist.github.com/Amegatron/06da8770e46e116b05f1c290cb0d56fc > > Looking forward to your feedback. > > Cheers, > Alexander Egorov. My first thought is that the current code, which assigns potentially null values, works fine if you throw an array_filter() at it at the end. $array = [ 'field1' => $param1, 'field2' => $param2, 'field3' => $param3_which_is_null, ]; $a = array_filter($array); // $a now omits the null fields My second thought is that this is yet another reason why using associative arrays as if they were a data structure is wrong and should be avoided; just use a class and everything will be fine. If you need to serialize it later, there's many serializers on the market if JsonSerialize isn't sufficient. So this doesn't seem like a worthwhile addition to me. --Larry Garfield