Why does this foreach loop fail to work?

[comp.lang.php]

[PHP]
$array = array($firstOrderByFieldIfClause, $groupByClause,
$orderByClause);
array_walk($array, create_function('&$a', '$a = substr($a, 0,
strrpos(trim($a), ",")); if ($a) $a = ", $a";'));
print_r("firstOrderByFieldIfClause = $firstOrderByFieldIfClause and
groupByClause = $groupByClause and orderByClause = $orderByClause<P>");
[/PHP]

Upon execution the fields within $array are never changed (verified by
checking code), and I don't understand why.

firstOrderByFieldIfClause = IF(image_creation_date IS NULL OR
image_creation_date = '' OR image_creation_date LIKE '0000%', 'x',
NULL) AS image_creation_date_alt, and groupByClause =
image_creation_date_alt, and orderByClause = image_creation_date_alt
desc,

Please review and help, I'm utterly lost!

Thanx
Phil

[Tim Roberts]

"comp.lang.php" <ph**************@gmail.comwrote:

>
[PHP]
$array = array($firstOrderByFieldIfClause, $groupByClause,
$orderByClause);
array_walk($array, create_function('&$a', '$a = substr($a, 0,
strrpos(trim($a), ",")); if ($a) $a = ", $a";'));
print_r("firstOrderByFieldIfClause = $firstOrderByFieldIfClause and
groupByClause = $groupByClause and orderByClause = $orderByClause<P>");
[/PHP]

Upon execution the fields within $array are never changed (verified by
checking code), and I don't understand why.

It certainly does. Try "var_dump($array);", and you'll see that all three
strings were changed.

Your mistake is in thinking that changes to $array(0) will also affect
$firstOrderByFieldIfClause.

The array constructor makes three new strings.
--
- Tim Roberts, ti**@probo.com
Providenza & Boekelheide, Inc.

[comp.lang.php]

Tim Roberts wrote:

"comp.lang.php" <ph**************@gmail.comwrote:

[PHP]
$array = array($firstOrderByFieldIfClause, $groupByClause,
$orderByClause);
array_walk($array, create_function('&$a', '$a = substr($a, 0,
strrpos(trim($a), ",")); if ($a) $a = ", $a";'));
print_r("firstOrderByFieldIfClause = $firstOrderByFieldIfClause and
groupByClause = $groupByClause and orderByClause = $orderByClause<P>");
[/PHP]

Upon execution the fields within $array are never changed (verified by
checking code), and I don't understand why.

It certainly does. Try "var_dump($array);", and you'll see that all three
strings were changed.

Your mistake is in thinking that changes to $array(0) will also affect
$firstOrderByFieldIfClause.

The array constructor makes three new strings.

I should have figured that all complex objects that take parameters
make clones of the parameters unless passed by reference. So that's
what I did:

$array = array(&$firstOrderByFieldIfClause, &$groupByClause,
&$orderByClause);

That did the trick, thanx!
Phil

--
- Tim Roberts, ti**@probo.com
Providenza & Boekelheide, Inc.