What are the implications of using PHP scripts in conjunction with AJAX calls for server-side processing and client-side display updates?

When using PHP scripts in conjunction with AJAX calls for server-side processing and client-side display updates, it is important to ensure that the PHP scripts are properly handling the incoming data from the AJAX calls and providing the correct response back to the client. This includes sanitizing and validating user input to prevent security vulnerabilities and ensuring that the PHP scripts are returning the data in a format that can be easily consumed by the client-side JavaScript code.

// Example PHP script to handle AJAX call and return data
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $data = json_decode(file_get_contents('php://input'), true);

    // Perform server-side processing with the data

    $response = [
        'success' => true,
        'message' => 'Data processed successfully',
        'data' => 'Processed data here'
    ];

    header('Content-Type: application/json');
    echo json_encode($response);
}