如何使用javascript（无jQuery）动画化滚动到页面顶部的动画？

Question

I would like execute a transition when pressing a button for the webpage to slowly scroll back to the top of the page. I know how to execute a transition using a change in class, but in this instance, how would i do it?

document.documentElement.scrollTop = 0;

Answer 1

document.body.scrollIntoView({behavior: 'smooth', block: 'start'});

Works also for any other DOM element. And for horizontal scrolling too.

Answer 2

You can use below code to move the top of the page.

 // When the user scrolls down 20px from the top of the document, show the button window.onscroll = function() { scrollFunction() }; function scrollFunction() { if (document.body.scrollTop > 20 || document.documentElement.scrollTop > 20) { document.getElementById("myBtn").style.display = "block"; } else { document.getElementById("myBtn").style.display = "none"; } } // When the user clicks on the button, scroll to the top of the document function topFunction() { document.body.scrollTop = 0; document.documentElement.scrollTop = 0; } 

 body { font-family: Arial, Helvetica, sans-serif; font-size: 20px; background: #ffffff; } #myBtn { display: none; position: fixed; bottom: 20px; right: 30px; z-index: 99; background-color: red; color: white; cursor: pointer; padding: 15px; border-radius: 4px; } #myBtn:hover { background-color: #555; } 

 <button onclick="topFunction()" id="myBtn" title="Go to top">Top</button> <div style="padding:30px">Scroll Down</div> <div style="padding:30px 30px 700px">This example demonstrates how to create a "scroll to top" button that becomes visible when the user starts to scroll the page.</div>