代码示例:(标识:eg_js_type_convert_constructor_isdate_2)
<!DOCTYPE html>
<html>
<body>

<h2>JavaScript 日期对象</h2>

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

function isDate(myDate) {
  return myDate.constructor === Date;
}
</script>

</body>
</html>
运行结果: