JSFiddle - React, Tailwind, and code Playground

HTML

<select>
	<option value="1">1</option>
	<option value="2">2</option>
	<option value="3">3</option>
	<option value="4">4</option>
	<option value="5">5</option>
</select>

JavaScript

document.querySelector("select").addEventListener("change", function (){
	alert(this.value);
}, false);