php/mongodb: how does references work in php?
- by harald
hello,
i asked this in the mongodb user-group, but was not satisfied with the answer, so -- maybe someone at stackoverflow can enlighten me:
the question was:
$b = array('x' => 1);
$ref = &$b;
$collection->insert($ref);
var_dump($ref);
$ref does not contain '_id', because it's a reference to $b, the handbook states. (the code snippet is taken from the php mongo documentation)
i should add, that:
$b = array('x' => 1);
$ref = $b;
$collection->insert($ref);
var_dump($ref);
in this case $ref contains the _id -- for those, who do not know, what the insert method of mongodb-php-driver does -- because $ref is passed by reference (note the $b with and without referencing '&').
on the other hand ...
function test(&$data) {
$data['_id'] = time();
}
$b = array('x' => 1);
$ref =& $b;
test($ref);
var_dump($ref);
$ref contains _id, when i call a userland function.
my question is: how does the references in these cases differ? my question is probably not mongodb specific -- i thought i would know how references in php work, but apparently i do not: the answer in the mongodb user-group was, that this was the way, how references in php work. so ... how do they work -- explained with these two code-snippets?
thanks in advance!!!
