- parse_url: documentation ( source)
- printf: documentation ( source)
<?php
$url = 'https://example.com/t/c/?cid=4924&sub1=342&asdjjn=2333';
$parts = parse_url($url);
$newUrl = 'https://example.com/t/t?ex=823948923849';
printf('%s&%s', $newUrl, $parts['query']);