JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="navigation">
    <li>
        <a href="index.php?option=com_content&amp;view=article&amp;id=6&amp;Itemid=109">Link 1</a></li>
<li>
   <a href="index.php?option=com_content&amp;view=article&amp;id=6&amp;Itemid=110">Link 2</a>
</li>
<li>
   <a href="index.php?option=com_content&amp;view=article&amp;id=6&amp;Itemid=111">Link 3</a>
</li>
</ul>

CSS

.current a{ color:green;}

JavaScript

url = 'http://www.domain-nane.com/index.php?option=com_content&view=article&id=6&Itemid=111';
var urlRegex =/Itemid=([0-9]+)/i;
var Itemid = url.match(urlRegex)[1];


var nodes = document.getElementById('navigation').childNodes;
var lis;
for(i=0; i<nodes.length; i++) {
    if(nodes[i].nodeType == 1){
      var lis = nodes[i];
      var aElem =   lis.childNodes[1];
      var AItemId = aElem.href.match(urlRegex)[1];
        if(Itemid == AItemId) {
            lis.className = lis.className + " current";
        }
    }
}