JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
    <h1 id='before'>This should show !</h1>
    <script>
    var a = document.getElementById('before').textContent;
    alert(a);
    var b = document.getElementById('after') ? document.getElementById('after').textContent : 'notfound';
        
        $(document).ready(function()  { var a = document.getElementById('before').textContent;
        
    var b = document.getElementById('after').textContent;
        console.log(b);
        });       
    </script>
    <h1 id="after">This should *not* show !</h1>
</body>