A function to display a nav menu saved as a transient

menu_transients.php

<?php
/**
 * Menu Transient, a function that helps with extremely large menus by storing the query in a transient
 * for ~24hrs. It can be used in template files to both store the transient and display the menu so there
 * is no need for multiple functions and queries.
 *
 * @param $name		string	A descriptive name of the menu (ex. "mobile-menu" or "quick-links").
 * @param $args		array 	The array of nav menu arguments.
 *
 * @return string	The HTML formatted nav menu
 */
function menu_transient( $name = '', $args = array() ) {

  // prepare the name to be used in the tranient key
	$name = str_replace( '-', '_', $name );

  // Get the transient if it exists
	$query = get_transient( $name . '_query' );

  // Otherwise, create a new transient
	if( $query === false ) {

		$query = wp_nav_menu($args);

    set_transient( $name . '_query', $query, 60*60*24/* 24 Hours */ );
	}

  // Display the nav menu
	echo $query;

}