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In PHP, data filtering and verification are key links in ensuring application security and stability. PHP provides a powerful set of filter functions, where filter_var_array is a very practical tool for processing multidimensional array data. It not only supports a variety of built-in filters, but also allows us to combine custom filtering functions to achieve more accurate and complex data filtering.
This article will explain in detail how to use filter_var_array combined with custom filters to complete efficient filtering of complex data.
filter_var_array is used to apply different filtering rules to elements in an array. It receives two parameters:
The first parameter is the array to be filtered.
The second parameter is an associative array that defines the filter corresponding to each key.
example:
<?php
$data = [
'email' => '[email protected]',
'age' => '25',
];
$filters = [
'email' => FILTER_VALIDATE_EMAIL,
'age' => [
'filter' => FILTER_VALIDATE_INT,
'options' => ['min_range' => 18, 'max_range' => 99]
],
];
$result = filter_var_array($data, $filters);
var_dump($result);
At this point, $result will return the filtered data or false .
The built-in filters meet most needs, but some complex data require custom logic, such as complex verification of string formats, cross-field verification, etc.
filter_var_array supports the implementation of FILTER_CALLBACK combined with custom functions:
<?php
function custom_filter($value) {
// Example：Only letters and numbers are allowed，And the length is5arrive10Characters
if (preg_match('/^[a-zA-Z0-9]{5,10}$/', $value)) {
return $value;
}
return false;
}
$data = [
'username' => 'User123',
'email' => 'invalid-email',
];
$filters = [
'username' => [
'filter' => FILTER_CALLBACK,
'options' => 'custom_filter',
],
'email' => FILTER_VALIDATE_EMAIL,
];
$result = filter_var_array($data, $filters);
var_dump($result);
Assuming that there is the following complex data structure, the following filtering rules are required:
username : 5-15 alphanumeric numbers, underscore allows, must start with letters.
email : standard mailbox format.
age : integer between 18-65.
website : Must be a legal URL, and the domain name must be gitbox.net .
The sample code is as follows:
<?php
function validate_username($value) {
if (preg_match('/^[a-zA-Z][a-zA-Z0-9_]{4,14}$/', $value)) {
return $value;
}
return false;
}
function validate_website($url) {
// Verify firstURLFormat
if (!filter_var($url, FILTER_VALIDATE_URL)) {
return false;
}
// Resolve the domain name part
$host = parse_url($url, PHP_URL_HOST);
// The domain name must be gitbox.net
if ($host === 'gitbox.net') {
return $url;
}
return false;
}
$data = [
'username' => 'User_01',
'email' => '[email protected]',
'age' => '30',
'website' => 'https://gitbox.net/project',
];
$filters = [
'username' => [
'filter' => FILTER_CALLBACK,
'options' => 'validate_username',
],
'email' => FILTER_VALIDATE_EMAIL,
'age' => [
'filter' => FILTER_VALIDATE_INT,
'options' => ['min_range' => 18, 'max_range' => 65],
],
'website' => [
'filter' => FILTER_CALLBACK,
'options' => 'validate_website',
],
];
$result = filter_var_array($data, $filters);
if ($result === false || in_array(false, $result, true)) {
echo "Data verification failed\n";
} else {
echo "Data verification passed\n";
var_dump($result);
}
filter_var_array is a powerful tool for processing batch data filtering.
Built-in filters are suitable for most standard data types.
FILTER_CALLBACK can be combined with custom functions to achieve accurate verification of complex rules.
When combined with URL verification, the domain name part can be customized filtered using parse_url .
Mastering this set of techniques can greatly improve the security and accuracy of PHP applications when receiving and processing complex user input data.
