​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>Document 对象</h1>
​
<h2>implementation 属性</h2>
​
<p>此文档是否具有 Tesla X 特征？</p>
​
<p id="demo"></p>
​
<script>
let answer = document.implementation.hasFeature("TESLA", "X");
document.getElementById("demo").innerHTML = answer;
</script>
​
</body>
</html>
​