<!DOCTYPE html>
<html>
<body>
<h1>Document 对象</h1>
<h2>defaultView 属性</h2>
<p>defaultView 属性返回当前窗口对象：</p>
<p id="demo"></p>
<script>
const view = document.defaultView;
document.getElementById("demo").innerHTML = view;
</script>
</body>
</html>