Manipulate a url string by adding GET parameters

Question

I want to add GET parameters to URLs that may and may not contain GET parameters without repeating ? or &.

Example:

If I want to add category=action

$url="http://www.acme.com";  // will add ?category=action at the end  $url="http://www.acme.com/movies?sort=popular";  // will add &category=action at the end 

If you notice I'm trying to not repeat the question mark if it's found.

The URL is just a string.

What is a reliable way to append a specific GET parameter?

Answer 1

Basic method

$query = parse_url($url, PHP_URL_QUERY);  // Returns a string if the URL has parameters or NULL if not if ($query) {     $url .= '&category=1'; } else {     $url .= '?category=1'; } 

More advanced

$url = 'http://example.com/search?keyword=test&category=1&tags[]=fun&tags[]=great';  $url_parts = parse_url($url); // If URL doesn't have a query string. if (isset($url_parts['query'])) { // Avoid 'Undefined index: query'     parse_str($url_parts['query'], $params); } else {     $params = array(); }  $params['category'] = 2;     // Overwrite if exists $params['tags'][] = 'cool';  // Allows multiple values  // Note that this will url_encode all values $url_parts['query'] = http_build_query($params);  // If you have pecl_http echo http_build_url($url_parts);  // If not echo $url_parts['scheme'] . '://' . $url_parts['host'] . $url_parts['path'] . '?' . $url_parts['query']; 

You should put this in a function at least, if not a class.