Add class to HTML attribute using jQuery : <p>I'd like to add the class <code>btn</code> to my hyperlink after the page loads.</p>

<p>Here is my current script:</p>

<p><strong>HTML</strong></p>

<pre><code>&lt;span id="callnow" class="mhMobile callnow"&gt;&lt;a href="tel:01234567890"&gt;01234567890&lt;/a&gt;&lt;/span&gt;
</code></pre>

<p><strong>JS</strong> </p>

<pre><code>(function(text){
    setTimeout(function(){
        document.querySelector(".callnow a").addClass("btn");
    }, 1000);
})()
</code></pre>

<p><strong>DEMO:</strong> <a href="https://jsfiddle.net/wnfmqsLf/" rel="nofollow noreferrer">https://jsfiddle.net/wnfmqsLf/</a></p>
