Joomla - displaying parent menu items

In Joomla 3 ,  get the level 1 (parent) menu items like title, alias and route with the given menu type.

            $app  = JFactory::getApplication();
            $menu = $app->getMenu();
            $menu_items = $menu->getItems('menutype', 'side-navigation');
            if(!empty($menu_items))
            {   
                foreach($menu_items as $item)
                {
                   $menu_title = $item->title;
                   $menu_alias = $item->alias;
                   $menu_route = $item->route;
                   $menu_level = $item->level;
                   if($menu_level==1)
                   {   
                 ?> 
                   <li><a href="<?php echo JURI::base(); ?><?php echo $menu_alias; ?>"> <?php echo $menu_title;?> </a></li>
                <?php
                   }
                }
            }

Joomla - Remove menu items permenantly

In Joomla, you can remove menu items by trashing them or unpublishing them. Trashing an item (and deleting it by emptying the trash) is forever, so it’s preferable to simply unpublish items, as you can easily publish them again later if you choose to do so.
As time goes on, however, the performance of your site can degrade significantly if you have too many unpublished items. If you have items (menu items, articles, and so on) that you know you’ll never use again, you should trash them.

Unpublish Joomla menu items

To unpublish menu items, follow these steps:

1. Click the Menu Manager icon in the control panel, or choose Menus→Menu Manager in any back-end page.
   Menu Manager opens.
2. Click the Menu Item tab at the top of the page.
   Menu Item Manager opens.
3. Place a checkmark in the box to the left of the names of the menu items you wish to unpublish.
   For this exercise, place checkmarks next to the following menu items:
   • Using Joomla!
   • The Joomla! Community
   • The Joomla! Project
4. Click the Unpublish button at the top of the page.
5. View the front page again.

Trash menu items in Joomla

Besides unpublishing items in Joomla, you can delete them by trashing them. Trash any items that you know you’ll never use again. Here’s how:

1. Click the Menu Manager icon in the control panel, or choose Menus→Menu Manager in any back-end page.
   Menu Manager opens.
2. Click the Menu Item tab at the top of the page.
   Menu Item Manager opens.
3. Check the check box at the beginning of the item’s row.
4. Click the trash icon in the top-right corner of the page.
   You’ve just moved the item to the trash. To permanently delete it, you have to tell Joomla to do so.
5. From the Select State drop-down menu, choose Trash.
   Menu Item manager filters the trashed menu items.
6. For each item you want to delete, check the check box at the beginning of its row.
7. Click the Empty Trash icon in the top-right corner of the page.
   Trash Manager deletes the item forever.