JSFiddle - React, Tailwind, and code Playground

HTML

<input type="radio" name="gender" value="Male" id = "gender"/>Male
<input type="radio" name="gender" value="Female" id = "gender"/>Female
<div id
<input type="button" id="checkbutton" value="check">

JavaScript

$("#checkbutton").click(function()
{
if(!$('[name="gender"]:checked').size())
     alert("error");
else
    alert("ok");
}
);