add form validation in jquery code example

Example 1: form validation using jquery

<script src="https://cdn.jsdelivr.net/jquery.validation/1.16.0/jquery.validate.min.js"></script>
then add javascript code:
$(document).ready(function() {
   $("#form").validate();
});
</script>

Example 2: form validation using jquery

<html>
<body>
<h2>Validation of a form</h2>
<form id="form" method="post" action="">
First name:<br>
<input type="text" name="firstname" value="john">
<br>
Last name:<br>
<input type="text" name="lastname" value="Doe">
<br>
Email:<br>
<input type="email" name="u_email" value="[email protected]">
<br>
<br><br>
<input type="submit" value="Submit">
</form>
</body>
</html>