JSFiddle - React, Tailwind, and code Playground

HTML

<div id="header" class="header">
<a id="navicon">| | | |</a>
<ul id="topbar" class="topbar hidden">

  <li><a class="links">Profile</a></li>
  <li><a class="links">Work Experience</a></li>
  <li><a class="links">Skills and Qualification</a></li>
  <li><a class="links">Education</a></li>
  <li><a class="links">Work Sample</a></li>
  <li><a class="links">Contact</a></li>


</ul>

</div>

CSS

#topbar { display:none; }

JavaScript

$("a#navicon").click(function () { 
 var obj = $(this).siblings("ul").attr("id");
alert (obj);
 
  if($('ul#'+obj).has(css('display','none')){
       alert("Display of the element is none!")
    } 
	
	else {
       alert("The element is visible")
		}


    });