WordPress - Clean wp_nav_menu

clean-wp_nav_menu.php

//Deletes all CSS classes and id's, except for those listed in the array below
function custom_wp_nav_menu($var) {
  return is_array($var) ? array_intersect($var, array(
    //List of allowed menu classes
    'first',
    'last',
    'current_page_item',
    'current_page_parent',
    'current_page_ancestor',
    'current-menu-ancestor',
    'active'
    )
  ) : '';
}
add_filter('nav_menu_css_class', 'custom_wp_nav_menu');
add_filter('nav_menu_item_id', 'custom_wp_nav_menu');
add_filter('page_css_class', 'custom_wp_nav_menu');

//Replaces "current-menu-item" (and similar classes) with "active"
function current_to_active($text){
  $replace = array(
    //List of menu item classes that should be changed to "active"
    'current_page_item' => 'active',
    'current_page_parent' => 'active',
    'current_page_ancestor' => 'active',
    'current-menu-ancestor' => 'active'
  );
  $text = str_replace(array_keys($replace), $replace, $text);
    return $text;
}
add_filter ('wp_nav_menu','current_to_active');

//Deletes empty classes and removes the sub menu class
function strip_empty_classes($menu) {
  $menu = preg_replace('/ class=""| class="sub-menu"/','',$menu);
  return $menu;
}
add_filter ('wp_nav_menu','strip_empty_classes');