Cacher is the code snippet organizer for pro developers

function my_wp_nav_menu_args( $args = '' ) {

if( is_user_logged_in() ) { 
	$args['menu'] = 'logged-in';
} else { 
	$args['menu'] = 'logged-out';
} 
	return $args;
}
add_filter( 'wp_nav_menu_args', 'my_wp_nav_menu_args' );