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What's the scroll from the bottom?

importance: 5

The elem.scrollTop property is the size of the scrolled out part from the top. How to get “scrollBottom” – the size from the bottom?

Write the code that works for an arbitrary elem.

P.S. Please check your code: if there’s no scroll or the element is fully scrolled down, then it should return 0.

The solution is:

let scrollBottom = elem.scrollHeight - elem.scrollTop - elem.clientHeight;

In other words: (full height) minus (scrolled out top part) minus (visible part) – that’s exactly the scrolled out bottom part.