PHP - Extracting a property from an array of objects

Question

I\'ve got an array of cats objects:

$cats = Array
    (
        [0] => stdClass Object
            (
                [id] => 15
            ),
                 


        

Answer 1

function extract_ids($cats){
    $res = array();
    foreach($cats as $k=>$v) {
        $res[]= $v->id;
    }
    return $res
}

and use it in one line:

$ids = extract_ids($cats);