JSFiddle - React, Tailwind, and code Playground

HTML

<div id="liveUpdate"></div>

JavaScript

(function() {
    var update = document.getElementById("liveUpdate");
    var count = {
        digit: 0,
        increment: function() {
            var interval = setInterval(function() {
                if (++count.digit == 10) {
                    clearInterval(interval);
                    count.decrement();
                }
                update.innerHTML = count.digit;
            }, 500);
        },
        decrement: function() {
            var interval = setInterval(function() {
                if (--count.digit == -1) {
                    clearInterval(interval);
                }
                update.innerHTML = count.digit;
            }, 500);
        }
    };
    count.increment();
})();