Add the below code at the end of your theme’s functions.php file or you can also add the below code inside your site-specific plugin.
// display all wp query variables
var_dump( $wp_query->query_vars );
If you like this question & answer and want to contribute, then write your question & answer and email to freewebmentor[@]gmail.com. Your question and answer will appear on FreeWebMentor.com and help other developers.