代码示例:(标识:js_date_isdate)
<!DOCTYPE html>
<html>
<body>

<h1>JavaScript Date 对象</h1>

<p>这个“自制的” isDate () 函数在日期上使用时返回 true:</p>

<p id="demo"></p>

<script>
const myDate = new Date();
document.getElementById("demo").innerHTML = isDate(myDate);

function isDate(myDate) {
  return myDate.constructor.toString().indexOf("Date") > -1;
}
</script>

</body>
</html>
运行结果: