TextTrackList: length property
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
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().
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 |
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| HTML # dom-texttracklist-length |
Browser compatibility
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Legend
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- Full support
- Full support