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