<?php

/**

* Sanitizes form input using default values as a fallback.

*

* @param array $postData Array of form data.

* @param array $defaults Array of default values.

* @return array Sanitized form data.

*/

function sanitizeFormInput(array $postData, array $defaults): array

{

$sanitizedData = [];

foreach ($defaults as $key => $defaultValue) {

// Get the user-submitted value, or the default if not provided.

$value = isset($postData[$key]) ? $postData[$key] : $defaultValue;

// Sanitize the input. This is a basic example; adjust as needed.

$sanitizedData[$key] = trim(htmlspecialchars($value));

}

return $sanitizedData;

}

// Example Usage:

// Assume $postData contains data from a form submission.

// Assume $defaults defines the default values for the form fields.

// Example defaults

$defaults = [

'name' => 'Guest',

'email' => '',

'message' => 'Please enter a message.',

'age' => 0,

'city' => 'Unknown'

];

// Example form data (simulated)

$postData = [

'name' => 'John Doe',

'email' => 'john.doe@example.com',

'message' => 'This is a test message.',

'age' => '30',

'city' => ''

];

$sanitizedData = sanitizeFormInput($postData, $defaults);

// Now $sanitizedData contains the sanitized values, using defaults where necessary.

print_r($sanitizedData);

?>