It is very important input by users are validated before they are sent for processing. Not validating what users enter can lead to a very big security breach and could make your website susceptible to hackers. PHP has a large number of filters for validation and sanitization, but we’re only going to see that of the Email, URL and IP address.
Let’s take a look at these validation filters and how they work.
Validating Email:
Function :– filter_var($value, FILTER_VALIDATE_EMAIL)
<?php
$email = "knowledgecorner@gmail.com";
if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
echo "This ($email) email is valid.";
}
else {
echo "This ($email) is not valid.";
}
?>
Validating URL:Function – filter_var($value, FILTER_VALIDATE_URL)
<?php
$url = 'knowledgecorner.com';
if (filter_var($url, FILTER_VALIDATE_URL)) {
echo "This ($url) URL is valid.";
}
else {
echo "This ($url) URL is not valid.";
}
?>
Validating IP address:Function – filter_var($value, FILTER_VALIDATE_IP)
<?php
$ip = '10.199.212.2';
if (filter_var($ip, FILTER_VALIDATE_IP)) {
echo "This ($ip) IP address is valid.";
}
else {
echo "This ($ip) IP address is not valid.";
}
?>



