https://www.afpsiembra.com/js/toTopScript.js

1const select = (el, all = false) => {
2    el = el.trim()
3    if (all) {
4        return [...document.querySelectorAll(el)]
5    } else {
6        return document.querySelector(el)
7    }
8}
9
10const onscroll = (el, listener) => {
11    el.addEventListener('scroll', listener)
12}
13
14let backtotop = select('.toTop')
15if (backtotop) {
16    const toggleBacktotop = () => {
17        if (window.scrollY > 100) {
18            backtotop.classList.add('active-toTop')
19        } else {
20            backtotop.classList.remove('active-toTop')
21        }
22    }
23    window.addEventListener('load', toggleBacktotop)
24    onscroll(document, toggleBacktotop)
25}