The Roman numerals leetcode question

First interview - general JS questions / Leetcode: - currying - var/let/const scope undefined in function being declared and executed - Binary tree question (parent/child nodes) and finding closest common parent of 2 nodes Second interview - home assignment - mock some json/array to represent a 'nested dropdown menu' - create the menu button - dropdowns from menu and from each further sub-item can open another dropdown etc. etc., meaning a potentially infinite dropdown menu design. - context-menu right click with add/delete/rename to modify the data - load/save buttons for different data source