你可以设置为 undefined 来清空对象 - 在线编辑器

          <p>对象可以设置为 <b>undefined</b> 来清空。</p>
<p id="demo"></p>
<script>
  var person = {
    firstName: "John",
    lastName: "Doe",
    age: 50,
    eyeColor: "blue"
  };
  var person = undefined;
  document.getElementById("demo").innerHTML = typeof person;
</script>
        