- var_dump: documentation ( source)
- parse_str: documentation ( source)
- array_merge: documentation ( source)
- parse_url: documentation ( source)
- http_build_query: documentation ( source)
<?php
$url = 'http://mysite.com/hello/world?look_at=me';
$query = parse_str(parse_url($url, PHP_URL_QUERY));
var_dump($query);
?>
<a href="?<?= http_build_query(array_merge($query, ['category' => 'val'])) ?>">Категория каталога</a>
<a href="?<?= http_build_query(array_merge($query, ['sort' => 'price'])) ?>">Сортировать по цене</a>