JSFiddle - React, Tailwind, and code Playground

by Fiddel

HTML

<button type="button" onclick="myFunction()">Count!</button>

<p id="demo">0</p>

http://www.w3schools.com/js/js_function_closures.asp

JavaScript

var add = (function () {
    var counter = 0;
    return function () {return counter += 1;}
})();

function myFunction(){
    document.getElementById("demo").innerHTML = add();
}