GlobalEventHandlers.onscroll
The onscroll
property of the
GlobalEventHandlers
mixin is an event handler that
processes scroll
events.
The scroll
event fires when the document view or an element has been
scrolled, whether by the user, a Web API, or the
user agent.
Note: Don't confuse onscroll
with
onwheel
!
onwheel
handles general wheel rotation, while onscroll
handles scrolling of an object's content.
Syntax
target.onscroll = functionRef
Value
functionRef
-
A function name, or a function expression. The function receives a
UIEvent
object as its sole argument.
Only one onscroll
handler can be assigned to an object at a time.
For greater flexibility, you can pass a scroll
event to the
EventTarget.addEventListener()
method instead.
Example
This example monitors scrolling on a <textarea>
, and logs the
element's vertical scroll position accordingly.
HTML
<textarea>1 2 3 4 5 6 7 8 9</textarea>
<p id="log"></p>
CSS
textarea {
width: 4rem;
height: 8rem;
font-size: 3rem;
}
JavaScript
const textarea = document.querySelector('textarea');
const log = document.getElementById('log');
textarea.onscroll = logScroll;
function logScroll(e) {
log.textContent = `Scroll position: ${e.target.scrollTop}`;
}
Result
Specifications
Specification |
---|
HTML Standard # handler-onscroll |
Browser compatibility
BCD tables only load in the browser