<html><body><h2>JavaScript Date 日期对象</h2><p>这个“自制”的 isDate() 函数在用于日期时返回 true：</p><p id="demo"></p><script>var myDate = new Date();document.getElementById("demo").innerHTML = isDate(myDate);function isDate(myDate) { return myDate.constructor === Date;}</script></body></html>