VideoTrackList: length property
The read-only VideoTrackList
property length
returns the number of entries in the
VideoTrackList
, each of which is a VideoTrack
representing
one video track in the media element.
A value of 0 indicates that there are no video tracks in the media.
Value
A number indicating how many video tracks are included in the
VideoTrackList
. Each track can be accessed by treating the
VideoTrackList
as an array of objects of type VideoTrack
.
Examples
This snippet gets the number of video tracks in the first <video>
element found in the DOM by querySelector()
.
js
const videoElem = document.querySelector("video");
let numVideoTracks = 0;
if (videoElem.videoTracks) {
numVideoTracks = videoElem.videoTracks.length;
}
Note that this sample checks to be sure HTMLMediaElement.videoTracks
is
defined, to avoid failing on browsers without support for VideoTrack
.
Specifications
Specification |
---|
HTML Standard # dom-videotracklist-length-dev |
Browser compatibility
BCD tables only load in the browser