Migration to PHP 8.3 confusion regarding array_sum / array_product behavior

[DanielRuf]

I stumbled upon this PR during a migration to PHP 8.3:

array_sum() and array_product() now warn when values in the array cannot be converted to int/float.

This seems to be not the case. As we can see at https://3v4l.org/lKNfW#v8.3.20, the value (string) 3Hallo is converted to 3. So either the warning Warning: A non-numeric value encountered in or the documentation is not right.

Since cannot be converted to int/float. is not the case here, does this mean the documentation is inaccurate?

Originally posted by @DanielRuf in #3106 (comment)

[DanielRuf]

Relevant PR: php/php-src#10161

[joshtrichards]

It's being converted properly. At least according to PHP casting logic - e.g.

https://www.php.net/manual/en/language.types.integer.php#language.types.integer.casting.from-string

https://www.php.net/manual/en/language.types.float.php#language.types.float.casting.from-string

https://www.php.net/manual/en/language.types.numeric-strings.php#language.types.numeric-string.conversion

So docs and implementation appear correct to me.

[DanielRuf]

@joshtrichards thanks for your reply.

I think my assumption that Warning: A non-numeric value encountered in should be also mentioned in the docs (probably just a general warning introduced in PHP 8.3.0 - same version when the mentioned PR was merged) is not correct.

Because Warning: A non-numeric value encountered in happens when successfully converted to int /float.

But is not supported on type is the only warning, that the documention for array_sum / array_product points to when writing array_sum() and array_product() now warn when values in the array cannot be converted to int/float. (see https://github.com/php/php-src/pull/10161/files#diff-8c0fc345d1128e0103a06755fa6a666197a62fdbae28a9c5e53a17726781c45eR18).

I'll cover this case by doing some checks / filtering with is_numeric() before using strings with a leading number (which otherwise would result in a warning and get successfully converted to int/float). I'm probably just missing a mention of general warnings introduced for all arithmetic functions / expressions directly in the affected function documention pages instead of in a simple migration / upgrade document (because personally I see this as a side-effect that is undocumented).

It seems checking even the smallest warning still makes sense in PHP and fixing the actual root cause (which means here checking the provided values for the correct types / contents before using them for calculations, due to still quite weak type handling and type juggling of PHP compared to more strict languages like TypeScript).

Closing as obsolete.

[DanielRuf]

Unfortunately https://www.php.net/manual/en/language.types.numeric-strings.php#language.types.numeric-string.conversion says nothing about the change in array_sum / array_product in PHP 8.3 resulting in the warning from PHP 8.0.

I'll try to write more defensive code (type guards and assertions (https://github.com/beberlei/assert, https://github.com/webmozarts/assert), general checks (https://www.php.net/manual/en/function.is-numeric.php)) to catch these edge-cases.