JSFiddle - React, Tailwind, and code Playground
JavaScript
/**
* Count up and down - linear
*/
var t = 100,
i = 1,
s = 1;
var a = function(){
i += s;
s *= ((i % t) == 0 ? -1 : 1);
document.body.innerHTML = i;
requestAnimationFrame(a);
}
a();