Add “parent” class to parent menu items

Is there a good way to add a class of “parent” to list items that have children using wp_nav_menu?

I’ve found a couple of solutions online but non seem to have the desired effect.

This may not be the ideal solution, depending on what you need the class for, but you could add a “parent” class via JavaScript. The line below uses the jQuery :has() selector:

$('#nav-id').find('li:has(ul)').addClass('parent');