ArrayAccess and foreach

[staabm]

Description

the docs describe foreach as

The foreach construct provides an easy way to iterate over arrays and Traversable objects. foreach will issue an error when used with a variable containing a different data type or with an uninitialized variable.

while working on a PHPStan issue, I recently discovered that php also allows to iterate over an object implementing ArrayAccess, even though thats neither Traversable nor is_iterable nor is_array.

see https://3v4l.org/NMrFZ#veol

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I am a bit lost whether

• this actually works like expected?
• this needs a doc update?
• php-src misses to issue a error/warning?
• whether I am overlooking something

PHP Version

any since PHP 7.1+

Operating System

macOS sequioa

[nielsdos]

This isn't related to ArrayAccess. You can iterate over any object: https://3v4l.org/VbfLa#v7.4.33

[nielsdos]

Note that the wording says "provides an easy way to (...)", it does not say this is limitative.

[staabm]

but it says

foreach will issue an error when used with a variable containing a different data type...

which it does not in this case

[nielsdos]

The variable in this case is $o and it says containing. However, what it means to "contain a different data type", I have no idea.
This looks like a docs issue.