JSFiddle - React, Tailwind, and code Playground

by Vaniljs

HTML

<select id="cat">
    <option>Выберите</option>
    <option>Category 1</option>
    <option>Category 2</option>
</select>


<p>Выбрано: <span id="info1"></span></p>

JavaScript

var selectedDevice = null;

function onChangeSelect(select) {
  selectedDevice = this.options[this.selectedIndex];
  document.querySelector('#info1').innerHTML = selectedDevice.text;
}

document.getElementById('cat').addEventListener('change', onChangeSelect);