Back to Content

TextTrackList: length property

files/en-us/web/api/texttracklist/length/index.md

latest1.1 KB
Original Source

{{APIRef("HTML DOM")}}

The read-only {{domxref("TextTrackList")}} property length returns the number of entries in the TextTrackList, each of which is a {{domxref("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 {{domxref("TextTrack")}}.

Examples

This snippet gets the number of text tracks in the first media element found in the {{Glossary("DOM")}} by {{domxref("Document.querySelector", "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 {{domxref("HTMLMediaElement.textTracks")}} is defined, to avoid failing on browsers without support for {{domxref("TextTrack")}}.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}