关键技术：
元素获取；键盘、transitionend监听；类的添加、删除
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>JS Drum Kit
</title>
<link rel="stylesheet" href="style.css">
</head>
<body>
<div class="keys">
<div data-key="65" class="key">
<kbd>A
</kbd>
<span class="sound">clap
</span>
</div>
<div data-key="83" class="key">
<kbd>S
</kbd>
<span class="sound">hihat
</span>
</div>
<div data-key="68" class="key">
<kbd>D
</kbd>
<span class="sound">kick
</span>
</div>
<div data-key="70" class="key">
<kbd>F
</kbd>
<span class="sound">openhat
</span>
</div>
<div data-key="71" class="key">
<kbd>G
</kbd>
<span class="sound">boom
</span>
</div>
<div data-key="72" class="key">
<kbd>H
</kbd>
<span class="sound">ride
</span>
</div>
<div data-key="74" class="key">
<kbd>J
</kbd>
<span class="sound">snare
</span>
</div>
<div data-key="75" class="key">
<kbd>K
</kbd>
<span class="sound">tom
</span>
</div>
<div data-key="76" class="key">
<kbd>L
</kbd>
<span class="sound">tink
</span>
</div>
</div>
<audio data-key="65" src="sounds/clap.wav"></audio>
<audio data-key="83" src="sounds/hihat.wav"></audio>
<audio data-key="68" src="sounds/kick.wav"></audio>
<audio data-key="70" src="sounds/openhat.wav"></audio>
<audio data-key="71" src="sounds/boom.wav"></audio>
<audio data-key="72" src="sounds/ride.wav"></audio>
<audio data-key="74" src="sounds/snare.wav"></audio>
<audio data-key="75" src="sounds/tom.wav"></audio>
<audio data-key="76" src="sounds/tink.wav"></audio>
<script>
const keys = Array.from(document.querySelectorAll('.key'));
keys.forEach(key => key.addEventListener('transitionend', removeTransition));
document.onkeydown = function (event) {
var e = event || window.event || arguments.callee.caller.arguments[0];
const audio = document.querySelector(`audio[data-key="${e.keyCode}"]`);
const key = document.querySelector(`div[data-key="${e.keyCode}"]`);
if (!audio) return;
audio.currentTime = 0;
audio.play();
key.classList.add('playing');
}
function removeTransition(event) {
if (event.propertyName !== 'transform') return;
event.target.classList.remove('playing');
}
</script>
</body>
</html>
