Question

I have two arrays (records returned from a database query) that I’m merging. I then need to get a count of the elements in the combined array.

Here are the print_r results of the two original arrays:

Array(
    [0] => stdClass Object([id] => 25590)
    [1] => stdClass Object([id] => 40657)
    [2] => stdClass Object([id] => 60685)
    [3] => stdClass Object([id] => 61900)
    [4] => stdClass Object([id] => 65224)
)

Array(
    [0] => stdClass Object([id] => 88406)
)

Merged array created like this:

$licensed_users = array_unique(array_merge($lu, $lu2));

And the results of the merge (in this case there weren’t any duplicates, but there could be, hence the array_unique)

Array(
    [0] => stdClass Object([id] => 25590)
    [1] => stdClass Object([id] => 40657)
    [2] => stdClass Object([id] => 60685)
    [3] => stdClass Object([id] => 61900)
    [4] => stdClass Object([id] => 65224)
    [5] => stdClass Object([id] => 88406)
)

The array is assigned to a session variable, to be used on another page:

    $_SESSION['licensed_users'] = $licensed_users;

I now want to know how many elements are in the merged array via the session variable.

count($_SESSION['licensed_users'])

I would expect this to return 6. Instead, it returns 1. Any idea why?

EDITED TO ADD CODE FOR @SURREALDREAMS

$_SESSION['licensed_users'] = array_unique(array_merge($lu, $lu2));
print_r($lu);
print_r($lu2);
print_r($_SESSION['licensed_users']);
echo "there are ". count($_SESSION['licensed_users']) . " licensed users";

This code returns the following:

$lu Array(
    [0] => stdClass Object([id] => 25590)
    [1] => stdClass Object([id] => 40657)
    [2] => stdClass Object([id] => 60685)
    [3] => stdClass Object([id] => 61900)
    [4] => stdClass Object([id] => 65224)
)

$lu2 Array(
    [0] => stdClass Object([id] => 88406)
)

$_SESSION['licensed_users'] Array(
    [0] => stdClass Object([id] => 25590)
)

The echo line returns 1.

If I try it the other way you suggested:

$licensed_users = array_unique(array_merge($lu, $lu2));
$_SESSION['licensed_users'] = $licensed_users;
echo "there are ". count($_SESSION['licensed_users'], COUNT_RECURSIVE) -1 . " licensed users";

the arrays returned have the same contents, but the echo line returns -1.

Answer 1

The issue is in the array_unique() call. From the documentation:

Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is the same.

Those objects are being converted to strings before being compared. You may have to manually prune them based on some other property.