JSFiddle - React, Tailwind, and code Playground

HTML

<div id="myDiv">Hide/Show</div>

JavaScript

function toggleMenu(id) {
    var a = document.getElementById(id);
    if(a.style.display==='none') {
        a.style.display='block';
    } else { 
        a.style.display="none";
    }
};
setInterval(function() {
    toggleMenu('myDiv');
}, 500);