JSFiddle - React, Tailwind, and code Playground

HTML

<select name="myselect">
  <option value="Value 1">Red</option>
  <option value="Value 2">Green</option>
  <option value="Value 3" selected="selected">Blue</option>
</select>

JavaScript

var formElement=document.getElementsByName("myselect")[0];
var val=formElement.options[formElement.selectedIndex].value;

alert(val);