PHP Development Basics Tutorial Advanced Filters

1. Check whether a number is within a range

The following example uses the filter_var() function to detect whether an INT type variable is between 1 and Within 200:

The code is as follows

<?php
$int = 134;
$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");
}
?>

The output is shown in the picture on the right

2. Detect IPv6 address

The following example uses the filter_var() function to detect whether a $ip variable is an IPv6 address:

<?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");
}
?>

The output is shown on the right

three , Detect URL - must contain QUERY_STRING (query string)

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

The code is as follows

<?php
$url = "http://www.php.cn";

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");
}
?>

The output result is shown in the picture on the right

4. Remove characters with ASCII values ​​greater than 127

Move Except characters with ASCII value greater than 127

The code is as follows

<?php
$str = "<h1>Hello WorldÆØÅ!</h1>";

$newstr = filter_var($str, FILTER_SANITIZE_STRING, FILTER_FLAG_STRIP_HIGH);
echo $newstr;
?>

The output result is shown in the picture on the right

Note: For more PHP filter applications, please see the PHP manual