<!DOCTYPE html> <html> <body> <h1>JavaScript</h1> <p>可以通过将值设置为 <b>undefined</b> 来清空对象。</p> <p id="demo"></p> <script> let person = {firstName:"Bill", lastName:"Gates", age:19, eyeColor:"blue"}; person = undefined; document.getElementById("demo").innerHTML = person; </script> </body> </html>