WordPress Footer Navigation as String

functions.php

if (!function_exists('theme_footer_menu')) :
function theme_footer_menu($args = array('theme_location' => 'secondary', 'seperator' => '•')) {

  $args['seperator'] = ($args['seperator'] != '') ? ' ' . $args['seperator'] . ' ' : ' ';
  if ($args['theme_location'] == '') {
    return false;
  } else {
    if ( ( $locations = get_nav_menu_locations() ) && isset( $locations[ $args['theme_location'] ] ) ) {
      $menu = wp_get_nav_menu_object( $locations[ $args['theme_location'] ] );
      $menu_items = wp_get_nav_menu_items($menu->term_id);
      $menu_string = '';
      foreach ( (array) $menu_items as $key => $menu_item ) {
        $menu_string .= $args['seperator'] . '<a href="' . $menu_item->url . '">' . $menu_item->title . '</a>';
      }
      echo $menu_string;
    }
  }
}
endif;