$page = isset($_GET['page']) ? $_GET['page'] : '1' // setting the default value to '1' or in php 7 the more shortcut way is $page = $_GET['page'] ?? '1';
$page = isset($_GET['page']) ? $_GET['page'] : '1' // setting the default value to '1' or in php 7 the more shortcut way is $page = $_GET['page'] ?? '1';