​x
 
<!DOCTYPE html>
<html>
<body>
<h1>DOMTokenList 对象</h1>
​
<h2>length 属性</h2>
​
<p>"demo" 中的 class token 的数目是：</p>
<p id="demo" class="c1 c2 c3"></p>
​
<script>
const list = document.getElementById("demo").classList;
let number = list.length;
​
document.getElementById("demo").innerHTML = number;
</script>
​
</body>
</html>
​