JavaScript音频对象如何点击下一步播放下一首曲目

var audio = new Audio();

var playlist = [
  "曲目1.mp3",
  "曲目2.mp3",
  "曲目3.mp3"
];

var currentTrackIndex = 0;

function playTrack(index) {
  audio.src = playlist[index];
  audio.play();
  currentTrackIndex = index;
}

<button onclick="playNextTrack()">下一首</button>

function playNextTrack() {
  currentTrackIndex++;
  if (currentTrackIndex >= playlist.length) {
    currentTrackIndex = 0;
  }
  playTrack(currentTrackIndex);
}