JSFiddle - React, Tailwind, and code Playground
HTML
<p>Click the button to create an array, then display its length.</p>
<button onclick="myFunction()">Try it</button>
<p id="demo"></p>
JavaScript
function myFunction() {
var mystring = ["1,2,3,4"];
var elements = mystring.toString().replace (/(^")|("$)/g, '').split(',').length;
document.getElementById("demo").innerHTML = elements;
}