What are the recommended methods for handling AJAX requests in PHP applications to improve user experience?

When handling AJAX requests in PHP applications, it is recommended to use asynchronous requests to improve user experience. This allows the user to interact with the webpage without having to wait for the entire page to reload. To achieve this, you can use the built-in PHP functions like `json_encode()` to send data back to the client-side JavaScript code.

// Example PHP code for handling AJAX requests
if(isset($_POST['data'])) {
    // Process the data received from the AJAX request
    $data = $_POST['data'];
    
    // Perform any necessary operations
    
    // Return a response back to the client-side JavaScript code
    $response = array('message' => 'Data processed successfully');
    echo json_encode($response);
    exit;
}