Copy the code code as follows:
<html>
<head>
<title>isNaN() method of global object</title>
<script>
/*
The isNaN() function is usually used to test the results of parseFloat() and parseInt() to determine whether they represent legal numbers.
Of course, you can also use the isNaN() function to detect arithmetic errors, such as using 0 as a divisor.
*/
document.write(isNaN(123) + "<br/>");//false
document.write(isNaN(-1.23) + "<br/>");//false
document.write(isNaN(5-2) + "<br/>");//false
document.write(isNaN(0) + "<br/>");//false
document.write(isNaN("Hello") + "<br/>");//true
document.write(isNaN("2005/12/12")+ "<br/>");//true
</script>
</head>
<body>
<div id="time"></div>
</body>
</html>