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Date: Fri, 29 May 2026 11:04:30 -0500
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Subject: Re: [PHP-DEV] [Pre-RFC] Null coalescing associative array elements
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From: larry@garfieldtech.com ("Larry Garfield")

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