JSFiddle - React, Tailwind, and code Playground

by antyrat

HTML

<input type="radio" name="mainPhoto" id="mainimg_1" value="1">
<input type="radio" name="mainPhoto" id="mainimg_2" value="2" checked>
<input type="radio" name="mainPhoto" id="mainimg_3" value="3">

JavaScript

$(function(){
    if($('input[name=mainPhoto]').is(':checked')) { 
        alert('checked');
    }
});