php filter advanced

Validate an Integer Within a Range

The following example uses the filter_var() function to check if a variable

is both of type INT, and between 1 and 200:

Example

<?php$int = 122;$min = 1;$max = 200;if (filter_var($int, FILTER_VALIDATE_INT, array("options" => array("min_range"=>$min, "max_range"=>$max))) === false) {  echo("Variable value is not within the legal range");} else {  echo("Variable value is within the legal range");}?>

Validate IPv6 Address

The following example uses the filter_var() function to check if the variable $ip is a valid

IPv6 address:

Example

<?php$ip = "2001:0db8:85a3:08d3:1319:8a2e:0370:7334";if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) === false) {  echo("$ip is a valid IPv6 address");} else {

  echo("$ip is not a valid IPv6 address");}?>

Validate URL - Must Contain QueryString

The following example uses the filter_var() function to check if the variable $url is a

URL with a querystring:

Example

<?php$url = "https://www.w3schools.com";if (!filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_QUERY_REQUIRED) === false) {  echo("$url is a valid URL with a query string");} else {

  echo("$url is not a valid URL with a query string");}?>

Remove Characters With ASCII Value > 127

The following example uses the filter_var() function to sanitize a string. It

will both remove all HTML tags, and all characters with ASCII value > 127, from

the string:

Example

<?php$str = "<h1>Hello WorldÆØÅ!</h1>";$newstr = filter_var($str, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH);echo $newstr;?>

Complete PHP Filter Reference

For a complete reference of all filter functions, go to our complete

PHP Filter Reference. Check each filter to see

what options and flags are available.

The reference contains a brief description, and examples of use, for each function!