Storing objects in an array with php

问题:

I have a function that pulls rows from a database, the content->id and content->type are them used to dynamically call amethod in an already loaded model to get and format the objects details. Once the object is returned it is added to array. All is well except that when i come to use the array although it has the correct number of items in it, they all contain the same object even though i know that they are returned different. Im at a complete loss with this one, any help/ideas whould be great!

The code is below:

foreach($query->result() as $content)
{
    $item = $this->{'mod_'.$content->type}->get($content->id);
    print_r($item);
    $items[] = $item;
}
print_r($items);

And the print_r statements produce this:

stdClass Object
(
    [id] => 30
    [type] => page
)

stdClass Object
(
    [id] => 29
    [type] => page
)

Array
(
    [0] => stdClass Object
        (
            [id] => 29
            [type] => page
        )

    [1] => stdClass Object
        (
           [id] => 29
           [type] => page
        )

)

回答1:

I would guess that the problem is that you get to the same object every time by reference from the get function and then add it by reference to the array, resulting in all items in the array being modified when the item gets modified in the get function. If that is the case, the following should work:

foreach($query->result() as $content)
{
    $item = $this->{'mod_'.$content->type}->get($content->id);
    print_r($item);
    $items[] = clone $item;
}
print_r($items);

回答2:

When you push $item to $items, it doesn't push the value $item points to but rather the reference itself. You'll need to initialize $item each time:

foreach($query->result() as $content)
{
    $item = new stdClass();
    $item = $this->{'mod_'.$content->type}->get($content->id);
    print_r($item);
    $items[] = $item;
}
print_r($items);

回答3:

You are probably returning references to the item, not the items themselves. It will always the last reference that $item points to.