Main Query (category)

add_query_arg()

Adds the specified GET parameters to the current or specified URL.

get_queried_object()

Sets and Gets the current queried object (complete information about the post, tags, categories, etc.).

get_queried_object_id()

Gets the ID of the current query object. It can be: any post, category, tag, other taxonomy element, author's archive.

get_query_var()

Gets query variables (query parameters) from WP_Query, which is set in the global variable $wp_query.

get_search_query()

Retrieves the contents of the search WordPress query variable.

get_status_header_desc()

Gets the text (message) of the HTTP response status code. For example, "Not Found".

is_embed()

Checks whether the request is a request for an embed post page.

is_robots()

Checks if this is a request to robots.txt file. A conditional tag.

redirect_canonical()

Defines whether the current request should be redirected to another URL. It performs the redirection if necessary.

remove_query_arg()

Removes the specified GET request parameters from the URL: ?parametr=value&param2=val2.

wp()

Sets the main query (WordPress environment).