Question

I have three arrays each having SimpleXML Objects in them. They are structured like so:

Array
(
    [0] => SimpleXMLElement Object
        (
            [post_id] => 1476
            [name] => Johnson Fisheries Ltd.
            [owner] => Mr. John Johnson
        )
)

I want to be able to compare all 3 arrays and filter out the differences so that the results have only the elements that are the same in all 3 arrays.

For example:

Array1
    (
        [0] => 1476
        [1] => 1560
        [2] => 1342
    )

Array2
    (
        [0] => 2454
        [1] => 1476
    )

Array3
    (
        [0] => 3412
        [1] => 7512
        [2] => 2454
        [4] => 1476
    )

The resulting array would only contain [0] => 1476

What’s the best way to do this? I’ve looked for a function that will compare arrays in this way but I have had no luck. Any ideas?

Any help is very appreciated!

Answer 1

Loop over your first array, checking it against the 2nd and 3rd using in_array, like this:

foreach($array1 as $post_id) {
    if(in_array($post_id, $array2) && in_array($post_id, $array3)) {
        // We have a winner!
    }
}