My JS needs to know how far the user is scrolled down the page.
If I run this code:
document.addEventListener('scroll', event => console.log(document.pageYOffset));
…or do the same thing with scrollY … or scrollTop … or swap ‘document’ in for ‘window’ … the console hears the event as I scroll, but always logs ‘undefined’. This happens across multiple HTML documents, in Chrome and Firefox, whether I have any CSS reset on or not. What am I doing wrong?