PHP advanced filter

Detect whether a number is within a range

The following example uses the filter_var() function to detect whether an INT type variable is within 1 to 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("变量值不在合法范围内");
 } else {
     echo("变量值在合法范围内");
 }
 ?>

##Detect IPv6 address

The following example uses the filter_var() function to detect whether a $ip variable is an 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 是一个 IPv6 地址");
 } else {
     echo("$ip 不是一个 IPv6 地址");
 }
 ?>

Detect URL - must contain QUERY_STRING (query string)

The following example uses the filter_var() function to detect whether $url contains the query string:

Example

<?php
 $url = "//m.sbmmt.com";
 
 if (!filter_var($url, FILTER_VALIDATE_URL, FILTER_FLAG_QUERY_REQUIRED) === false) {
     echo("$url 是一个合法的 URL");
 } else {
     echo("$url 不是一个合法的 URL");
 }
 ?>

Remove characters with ASCII values ​​greater than 127

The following example uses filter_var () function to remove characters with an ASCII value greater than 127 in a string. It can also remove HTML tags:

Example

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