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PHP Filter_var () Function

30 May 2019 1:38 pm || 0

What is filter_var?

filter_var() is a PHP function used to filters a variable with the help of a specified filter. In PHP programming language we can use filter_var() function to validate and sanitize a data such as an email id, IP address etc.

Basic Syntax of filter_var() Function

filter_var ( mixed $variable [, int $filter = FILTER_DEFAULT [, mixed $options ]] ) : mixed 



It is the value which needed to be filtered. 

Note: Scalar values are converted to string internally before getting filtered.

filter It is an optional parameter which represents the name or ID of the filter to be used. Default FILTER_DEFAULT will be used if this parameter is neglected. This will result in no filtering.
options Also, an optional parameter, It specifies single or multiple flags/option to be used, This parameter checks for possible flags and option for each filter 

Return Value

If successful it returns filtered value otherwise FALSE in the case fo failure

PHP Filter_var () Example:

This program is an example to validate and sanitize data using Filter_var function

<!DOCTYPE html>
                // Variable to check
                $email = "";
                // Remove all illegal characters from email
                $email = filter_var($email, FILTER_SANITIZE_EMAIL);
                // Validate e-mail
                if (filter_var($email, FILTER_VALIDATE_EMAIL)) {
                    echo("$email is a valid email address");
                } else {
                    echo("$email is not a valid email address");

Output is a valid email address