<script> $(document).ready(function(){ $(window).scroll(function(){ if ($(this).scrollTop() >= 100) { alert("100!"); } }); }); </script>

Why when I scroll the page does the alert not work?

  • Maybe instead of <body> , something with overflow:auto or overflow:scroll scrolls inside? - Surfin Bird

1 answer 1

Explicitly refer to window:

 $(document).ready(function() { $(window).scroll(function() { console.log($(window).scrollTop()); if ($(window).scrollTop() >= 100) { alert("100!"); } }); }); 
 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br>1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br>1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br>1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br>1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br>1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br> 1<br>1<br>