JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<body>

<p>An unordered list:</p>
<ul>
  <li>Coffee</li>
  <li>Tea</li>
  <span>Milk</span>
</ul>

<p>Click the button to find out how many li elements there are in this document.</p>

<button onclick="myFunction()">Try it</button>

<p id="demo"></p>

</body>
</html>

JavaScript

function myFunction() {
    var a = document.getElementsByTagName("LI");
    var b = document.getElementsByTagName("SPAN");

console.log(a.concat(b));
// expected output: Array ["a", "b", "c", "d", "e", "f"]
}