Change single variable value in querystring [closed]
Use
parse_url()to extract the query string from the URLparse_str()to split the query string into an arrayarray_merge()to add a new array"b" => 5http_build_query()to re-build a query stringThe remaining parts from the first step (protocol, host, path...) to re-build the full URL or - if you have the
HTTPpecl extension - ahttp_build_url()withHTTP_URL_JOIN_QUERYwill alleviate much of the work.