You can rebuild the URL and append query variables to the URL query by using this function. There are two ways to use this function; either a single key and value, or an associative array.
Using a single key and value:
add_query_arg( 'key', 'value', 'http://example.com' );
Using an associative array:
add_query_arg( array( 'key1' => 'value1', 'key2' => 'value2', ), 'http://example.com' );
Omitting the URL from either use results in the current URL being used
(the value of
Values are expected to be encoded appropriately with urlencode() or rawurlencode().
Setting any query variable's value to boolean false removes the key (see remove_query_arg()).
Important: The return value of add_query_arg() is not escaped by default. Output should be late-escaped with esc_url() or similar to help prevent vulnerability to cross-site scripting (XSS) attacks.