JSFiddle - React, Tailwind, and code Playground

HTML

<script src="&lt;link rel=&quot;stylesheet&quot; href=&quot;https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/css/bootstrap.min.css&quot; integrity=&quot;sha384-/Y6pD6FV/Vv2HJnA6t+vslU6fwYXjCFtcEpHbNJ0lyAFsXTsjBbfaDjzALeQsN6M&quot; crossorigin=&quot;anonymous&quot;&gt;"></script>
<div class="container">
        <div class="col-md-6 col-lg-6">

            <div class="form-group">
                <label for="email">Email</label>
                <input type="email" class="form-control" onFocus = "forValidation(this)" id="email" aria-describedby="emailHelp" placeholder="Enter email">
                
            </div>

        </div>
    </div>

    









    <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js" integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN" crossorigin="anonymous"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.11.0/umd/popper.min.js" integrity="sha384-b/U6ypiBEHpOf/4+1nzFpr53nxSS+GLCkfwBdFNTxtclqqenISfwAzpKaMNFNmj4" crossorigin="anonymous"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta/js/bootstrap.min.js" integrity="sha384-h0AbiXch4ZDo7tp9hKZ4TsHbi047NrKGLO3SEJAg45jXxnGIfYzk4Si90RDIqNm1" crossorigin="anonymous"></script>
    <script src="app.js"></script>

JavaScript

function forValidation(element){
    alert(element);
}