Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:116547
To: <internals@lists.php.net>
Date: Wed, 1 Dec 2021 14:56:07 +0100
Message-ID: <087101d7e6bb$30f27d70$92d77850$@webkr.de>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
Content-Language: de
Thread-Index: AdfmuYApeGDTVzCWRpW9yH4qTPFmeg==
Subject: Array comparison works completely different than documented?
From: andre@webkr.de (=?iso-8859-1?Q?Andr=E9_H=E4nsel?=)

The official documentation contains a conceptual description of array
comparison in
https://www.php.net/manual/en/language.operators.comparison.php#example-113.

Curiously the people who wrote the inofficial spec (I think the HHVM team at
Facebook?) came to
pretty much the same result, described in
https://github.com/php/php-langspec/blob/master/spec/10-expressions.md#relat
ional-operators:

> If both operands have array type, if the arrays have different numbers of
elements, the one
> with the fewer is considered less-than the other one, regardless of the
keys and values in each,
> and the comparison ends. For arrays having the same numbers of elements,
the keys from the left
> operand are considered one by one, if the next key in the left-hand
operand exists in the
> right-hand operand, the corresponding values are compared. If they are
unequal, the array
> containing the lesser value is considered less-than the other one, and the
comparison ends;
> otherwise, the process is repeated with the next element. If the next key
in the left-hand
> operand does not exist in the right-hand operand, the arrays cannot be
compared and FALSE is
> returned. If all the values are equal, then the arrays are considered
equal.

In reality, array comparison works completely different, it is however
unclear to me how exactly
it does work: https://3v4l.org/630vG

Do we know how this happened?