JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="some-list">
    <li><a href="#">One</a></li>
    <li><a href="#">Two</a></li>
    <li><a href="#">Three</a></li>
</ul>

JavaScript

(function(){
    var triggers = document.getElementById('some-list').getElementsByTagName('a');
            
    for (var i = 0, max = triggers.length; i < max; i += 1) {
        triggers[i].__i__ = i;
        triggers[i].addEventListener('mouseenter', function(e) {
            console.log(this.__i__);
        }, false);
    }

    
}());