Re: Re: Possible foreach bug; seeking advice to isolate the problem

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On Sat, Oct 23, 2010 at 6:48 PM, Jonathan Sachs <081012@xxxxxxxxxxx> wrote:

> Now that I understand it, I can see the same thing would happen if I
> wrote the equivalent code in C, and probably in Java.
>

Neither C nor Java have references as PHP does, and references in C++ cannot
be changed to point to a new location after being created. None of these
languages have this particular quirk. If you use pointers in C or C++, the
way you assign an address to a pointer makes it clear you are not
overwriting whatever the pointer currently points to, so again it's not a
problem.

In PHP we have a very common pattern of using a reference in foreach(), and
the loop variable continues to reference the last item after the loop exits.
Further, the second loop has to use the iteration variable as a
non-reference. If both loops use a reference variable, the problem
disappears:

    $x = array('a', 'b', 'c');
    foreach ($x as &$i) echo $i;
    > abc
    foreach ($x as &$i) echo $i;
    > abc

In my opinion, if you write code where a variable is a reference at point X
and a non-reference at point Y, you are asking for trouble. Simply separate
the loops into different functions or introduce a new loop variable.

David

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