Scroll event only fire when scrolling top

Question

I have a scroll function. It needs to alert when you scroll to bottom. Strangely, it only alerts when you scroll to top. What is the correct way to make it work when you scroll at bottom.

$(window).scroll(function() {
  if ($(window).scrollTop() == $(document).height() - $(window).height()){
    alert();
  });
});

Answer 1

You can use a flag to keep the current scroll or update it and then check the current position:

$(function () {
  cur = $(window).scrollTop();
  $(window).scroll(function() {
    if ($(window).scrollTop() < cur) {
      // Scrolled Up!
    } // Remove the extra `);` here.
  });
});

Answer 2

try this

$(window).scroll(function() {
 if ($(window).scrollTop() == $(document).height() - $(window).height()){
  alert();
 }  //Remove from here
});

Remove ) after the end of if block.