Remove parameters from string containing URL

There are built-in functions for this purpose, in PHP.

First you split the different part of the url : $parsedUrl = parse_url($url);

Here is the part you're looking for : $queryPart = $parsedUrl["query"];

You can split this query in parts with parse_str($queryPart, $_QUERY);

And Voilà ! var_dump($_QUERY);

You now can remove what you want from the $_QUERY Array : unset($_QUERY['parameter']);

And construct the Query String back : $queryPart = http_build_query($_QUERY);

Put the query back in the $parsed_url : $parsedUrl["query"] = $_QUERY;

And finally reconstruct the url : http_build_url('', $parsedUrl["query"] );

Here you go : http://php.net/manual/en/function.parse-url.php

$url = 'http://www.test.com/test.html?parameter=hey&parameter2=ho';
if ( $temp = strstr($url, '?', true) ) {
   $url = $temp;
}

If you just want to get rid of the second call, you can save the value in a variable. If it exists, do the assignment. If not, don't.

In PHP, if you don't need to do string interpolation (variables embedded in strings), you can just use single quotes. This is slightly faster and can help avoid bugs where you accidentally interpret something as a variable that was meant to be a literal $.

Note: there may be better overall solutions, but with so little context, it is hard to see them. For example, you don't say how you get this URL. Or what you're going to do with it. There might be better changes in one of those places.