title: React: Newbie: OAP : process child button click call parent function
body: <p>I come from the world of VB and other archaic languages and am trying to learn React/Javascript and have a simple problem - which I don't know how to solve, but I feel should be very simple.</p>
  <p>I have a functional component which renders a dropdown and a button, when the dropdown changes I am using usestate to keep track of the select item.</p>
  <p>I then have another functional component which 'hosts' this component - I guess the correct terminology is a parent.
  what I want to do is when the button is clicked I retrieve the dropdown item(which I have stored) and pass the value to a function in the 'host' component,which then does other stuff</p>
  <p>but I cant for the life of me figure out how to do this :-(</p>