How to check if menu with specific name exists

Question

How to check if a menu with name, for example 'topnavbar' exists in WordPress 3?

Answer 1

If you take a look at the code for the wp_nav_menu function, one of the first things it does is get the menu with that name, using the wp_get_nav_menu_object function. This function will return the menu, or false if it doesn't exist