I don't know if this was designed this way purposefully, but it makes sense to me. I see nothing out of the ordinary here. It makes for some really nasty code, but that can probably be said about all code that uses references.
If we try to simplify your example, we can see more clearly what's happening. First, let's take the loop out of the equation. $arr = []; ['foo' => &$v] = $arr; $v = 1; var_dump($arr); This creates an array with one element whose value is 1 and key is foo. That array restructuring is pretty much just a syntactic sugar for an assignment operation. So we can simplify this example further by replacing the array destructuring with this: $v = & $arr['foo']; Now, this looks like an average assignment of reference in PHP. The rules of assignment-by-ref state: > If you assign, pass, or return an undefined variable by reference, it will > get created. https://www.php.net/manual/en/language.references.whatdo.php#language.references.whatdo.assign Since array elements have similar logic to plain variables, this applies to undefined keys, too. The foo key in the example above is created initially with a NULL value. Using the variable alias we created, we can assign a different value to it. Coming back to your example from SO, the array destructuring in foreach is just a convoluted way of assignment-by-ref. After simplifying it, it becomes: foreach ($array as $key => $row) { $x = & $array[$key]['new']; $x = $row['bar']; } Which looks pretty normal to me. I would say it's definitely not a bug. It's just a mix of two PHP features that together make up for some confusing-looking code. -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
