Re: Array dereferencing of scalars

Yasuo Ohgaki wrote on 09/06/2015 11:44:

$v = NULL; $v[0][1][2][3][4][5][6][7][8][9]; // NULL this code is semantically wrong and I would like to have error/exception for such erroneous codes.

PHP considers an uninitialised variable to have the value NULL, and a NULL value to be coercable to any type, so this breaks down (logically, not necessarily literally) as follows: - coerce $v to array() - instantiate $v[0] as NULL - coerce $v[0] to array() - instantiate $v[0][1] as NULL - and so on... Raising a notice whenever the type is coerced would be inconsistent with other coercions (e.g. $foo = null; echo $foo + 1;). Raising a notice whenever the coerced array is actually accessed would result in a notice for every dimension, which would be very noisy. Ideally, it would give a single notice, as in the below, but I'm not sure how that would be implemented: $v = array(); var_dump($v[0][1][2][3][4][5][6][7][8][9]); // Notice: Undefined index: 0 // NULL Note that this is all rather different from the original case, which was about values which *cannot be coerced to array*. Regards, -- Rowan Collins [IMSoP]