JSFiddle - React, Tailwind, and code Playground

HTML

<select id="my_select">
  <option value="1">Foo</option>
  <option value="2">Bar</option>
  <option value="" selected="selected">Bork</option>
  <option value="3">Hey!</option>
</select>

JavaScript

var oS = document.getElementById("my_select");
alert(oS.options[oS.selectedIndex].value);