php remove single variable value pair from querystring

Question

I have a page that lists out items according to numerous parameters ie variables with values.

listitems.php?color=green&size=small&cat=pants&pagenum=1 etc.
To enable editing of the list, I have a parameter edit=1 which is appended to the above querystring to give:

listitems.php?color=green&size=small&cat=pants&pagenum=1&edit=1 So far so good.

When the user is done editing, I have a link that exits edit mode. I want this link to specify the whole querystring--whatever it may be as this is subject to user choices--except remove the edit=1.

When I had only a few variables, I just listed them out manually in the link but now that there are more, I would like to be able programmatically to just remove the edit=1.

Should I do some sort of a search for edit=1 and then just replace it with nothing?

$qs = str_replace("&edit=1, "", $_SERVER['QUERY_STRING']);
<a href='{$_SERVER['PHP_SELF']}?{$qs}'>return</a>;

Or what would be the cleanest most error-free way to do this.

Note: I have a similar situation when going from page to page where I'd like to take out the pagenum and replace it with a different one. There, since the pagenum varies, I cannot just search for pagenum=1 but would have to search for pagenum =$pagenum if that makes any difference.

• Sergiu Paraschiv: Use parse_str to turn it into an array that you can cleanly work with and then http_build_query to turn it back to a query string.

Answer 1

You can use parse_str() to parse the query string, remove the unwanted parts and build the new one via http_build_query() like this

parse_str($_SERVER['QUERY_STRING'], $params);
unset($params['edit']);
$new_query_string = http_build_query($params);