Maximum page jump in advance paging script

Use a sliding window for large page counts

Instead of printing hundreds of page links, show a small window around the current page and always provide access to the first and last pages.

<?php
$currentPage = max(1, filter_input(INPUT_GET, 'page', FILTER_VALIDATE_INT) ?: 1);
$totalPages = max(1, (int) ceil($totalRecords / $perPage));
$currentPage = min($currentPage, $totalPages);

$window = 2;
$from = max(1, $currentPage - $window);
$to = min($totalPages, $currentPage + $window);

for ($page = $from; $page <= $to; $page++) {
    if ($page === $currentPage) {
        echo '<strong aria-current="page">' . $page . ' ';
    } else {
        echo '<a href="?page=' . $page . '">' . $page . '</a> ';
    }
}
?>

This produces compact navigation even when the result set contains many pages. The original two-level paging logic remains below for comparison.