How can PHP developers optimize the user experience by retaining search results and POST variables during pagination?

When implementing pagination in a PHP application, developers can optimize the user experience by retaining search results and POST variables across pages. This can be achieved by storing the search query and POST variables in session variables and passing them along with the pagination links.

// Store search query and POST variables in session
session_start();

if(isset($_POST['search_query'])){
    $_SESSION['search_query'] = $_POST['search_query'];
}

// Retrieve search query and POST variables from session
$search_query = isset($_SESSION['search_query']) ? $_SESSION['search_query'] : '';

// Include search query and POST variables in pagination links
echo '<a href="page1.php?search_query='.$search_query.'">1</a>';
echo '<a href="page2.php?search_query='.$search_query.'">2</a>';
echo '<a href="page3.php?search_query='.$search_query.'">3</a>';