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<!DOCTYPE html> <html> <body> <h2>JavaScript 数据类型</h2> <p>任何变量均可通过设置值为 undefined 进行清空。其类型也将是 undefined。</p> <p id="demo"></p> <script> var person = {firstName:"Bill", lastName:"Gates", age:62, eyeColor:"blue"}; person = undefined; document.getElementById("demo").innerHTML = person; </script> </body> </html>