警告或通知未显示

Question

I have this code on PHP 7.2.x:

class Test
{
    public $prop = null;
}
$temp = new Test();
var_dump($temp->prop['fff']);

but why is not reported Warning when temp->prop['fff'] not exists?

Edit1: sorry I forget add this code here:

ini_set('display_startup_errors',1);
ini_set('display_errors',1);
error_reporting(-1); //all errors

Answer 1

I found something in the documentation:

Note:

Array dereferencing a scalar value which is not a string silently yields NULL, i.e. without issuing an error message.

So it seems to be by design, although it's not clear why. Personally I would at least expect an E_NOTICE.

There is a link to a bug report in the comments of that page, which in turn is marked as duplicate of another bug. This one seems to be neither fixed nor closed. So maybe it will be changed/fixed in the future.