JSFiddle - React, Tailwind, and code Playground

HTML

<body>
  <select id="category" name="category">
    <option value="men">Men</option>
    <option value="women">Women</option>
    <option value="youth">Youth</option>
    <option value="both">Both</option>
  </select>
  <input type="text" id="display" name="display" value="" />

JavaScript

var clection = {
  men: 27,
  women: 23,
  youth: 30,
  both: function() {
    return clection.men + clection.women;
  }
}
$(document).ready(function() {
  $('#category').change(function() {
		$("#display").val(eval('clection.'+$("#category").val()));
  });
});