Wp menu code - Navigation menu

 Activating navigation menu and using it with code.

function.php

add_theme_support('menus');

register_nav_menus(

    array(

        'primary-menu' => 'Primary Menu',

    )

)

<?php   echo get_home_url();  ?>

index.php

<?php 

$defaults = array( 

'container' => 'ul',

'theme_location' =>   'primary-menu',

'menu_class'  => 'nav navbar-nav '

);

wp_nav_menu( $defaults); 

?>

or

    $defaults = array( 

     'container' => 'ul',

     'theme_location' =>   'primary-menu',

     'menu_class'  => 'navbar-nav'

     );

     wp_nav_menu( $defaults);