The read-only AudioTrackList
property length
returns the number of entries in the
AudioTrackList
, each of which is an AudioTrack
representing one audio track in the media element. A value of 0 indicates that
there are no audio tracks in the media.
Syntax
var trackCount = AudioTrackList.length;
Value
A number indicating how many audio tracks are included in the
AudioTrackList
. Each track can be accessed by treating the
AudioTrackList
as an array of objects of type AudioTrack
.
Example
This snippet gets the number of audio tracks in the first <video>
element found in the DOM by querySelector()
.
var videoElem = document.querySelector("video");
var numAudioTracks = 0;
if (videoElem.audioTracks) {
numAudioTracks = videoElem.audioTracks.length;
}
Note that this sample checks to be sure HTMLMediaElement.audioTracks
is
defined, to avoid failing on browsers without support for AudioTrack
.
Specifications
Specification | Status | Comment |
---|---|---|
HTML Living Standard The definition of 'AudioTrackList.length' in that specification. |
Living Standard | |
HTML5 The definition of 'AudioTrackList.length' in that specification. |
Recommendation |
Browser compatibility
BCD tables only load in the browser