- substr: documentation ( source)
- str_replace: documentation ( source)
- http_build_query: documentation ( source)
<?php
$_GET = ['user' => 'Bob', 'location' => 'city'];
$queryStr = http_build_query($_GET);
echo $queryStr, PHP_EOL;
$sth = str_replace ("user", "somethingelse",$queryStr);
echo $sth, PHP_EOL;
$sth = substr($queryStr, 0, 9);
echo $sth, PHP_EOL;