JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>Array1</li>
    <li>Array2</li>
    <li id="element">Array3</li>
</ul>

JavaScript

var temp = document.getElementById('element').parentNode;
 var children = temp.childNodes;
 console.log(children.length);
var countElements = function(children) {
 var count=0;
 for (var i=0, m=children.length; i<m; i++) 
     if (children[i].nodeType===document.ELEMENT_NODE) 
         count++;
 return count;
}
console.info(countElements (children));