JSFiddle - React, Tailwind, and code Playground

HTML

<span id="myIcon">Id span!</span>
<span class="myIcon">Class span!</span>

JavaScript

var myIcon_class = document.getElementsByClassName('myIcon')[0]; //note, gets first element
    var myIcon = document.getElementById('myIcon')
    
    myIcon.onmouseover = function() {
        alert("hovered on ID!");
        return false;
    };
    
    myIcon_class.onmouseover = function() {
    		alert("hovered on class!");
        return false;
    }