JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">

<link rel="stylesheet" href="https://cdn.jsdelivr.net/jquery.switchery/0.8.1/switchery.min.css">

<script src="https://code.jquery.com/jquery-1.x-git.js"></script>

<script src="https://netdna.bootstrapcdn.com/bootstrap/3.0.0/js/bootstrap.min.js"></script>

<script src="https://cdn.jsdelivr.net/jquery.switchery/0.8.1/switchery.min.js"></script>

<br/>
<input type="checkbox" class="js-switch">

<br/>
<br/>
<h3>
Check State
</h3>

<input type="checkbox" class="js-switch2 js-check-click">
<button class="button js-check-click-button">Check state</button>

JavaScript

var elem = document.querySelector('.js-switch');
var init = new Switchery(elem);


//for second button
var elem2 = document.querySelector('.js-switch2');
var init2 = new Switchery(elem2);
var clickCheckbox = document.querySelector('.js-check-click');
var clickButton = document.querySelector('.js-check-click-button');

clickButton.addEventListener('click', function() {
  alert(clickCheckbox.checked);
});