JSFiddle - React, Tailwind, and code Playground

HTML

<div id="parent">
    <input type="radio" name="v" value="1"> 1<br>
    <input type="radio" name="v" value="2"> 2<br>
    <input type="radio" name="v" value="3" checked="checked"> 3<br>
</div>

JavaScript

document.getElementById('parent').addEventListener('change', function(e) {
    alert(e.target.value);

}, false);