Hello Readers ,

Today we will going to understand the concept of PHP filters to Sanitize and Validate data.

PHP filters are used to validate and sanitize external input.

Validating data = Determine if the data is in proper form.

Sanitizing data = Remove any illegal character from the data.

So in order to user the PHP filters their is a PHP function called "filter_var()".

Let's understand how we can use this function.

Suppose we are going to Sanitize and Validate a specific URL.

<?php
$url = "http://www.findnerd.com";

// Remove all illegal characters from a url
$url = filter_var($url, FILTER_SANITIZE_URL);

// Validate url
if (!filter_var($url, FILTER_VALIDATE_URL) === false) {
     echo("$url is a valid URL");
} else {
     echo("$url is not a valid URL");
}
?>

Output will be : http://www.findnerd.com is a valid URL.

Good Luck!