$array = array();
$array[] = 'files/cache';
$array[] = 'videos/src';

$files = array(); //has a lot more values
$files[] = 'config/site_theme_paths.php';
$files[] = 'files/cache/somefile.jpg';

foreach ($files as $files) {
    if(!in_array($file,$array)) { //only works for exact matches not if it contains
        echo $file.' is not in the array';
    }
}