rAF tutorial: basic animation

raf-basic-animation.js

const element = document.querySelector("span");
const finalPosition = 600;                                                                                    

const time = {
  start: performance.now(),
  total: 2000
};

const tick = now => {
  time.elapsed = now - time.start;
  const progress = time.elapsed / time.total;
  const position = progress * finalPosition;
  element.style.transform = `translate(${position}px)`;
  if (progress < 1) requestAnimationFrame(tick);
};

requestAnimationFrame(tick);