Conditional tags (others)
if( is_user_logged_in() ){
// user is authorized
}
is_user_logged_in() ----------Checks if the user is logged in.
have_comments() ----------Checks if there are comments to be displayed on the page.
comments_open() ----------Checks if comments are opened.
has_category() ----------Checks if the post is in at least one category.
has_tag() ----------Checks if the post is in at least one tag.
has_term() ----------Checks if the post is in at least one taxonomy term.
has_excerpt() ----------Checks if the post has an excerpt (quote, short description).
is_nav_menu() ----------Checks if there is a menu by ID, slug or name.
has_nav_menu() ----------Checks if registered menu area have an attached menu.
has_shortcode() ----------Checks if content contains the specified shortcode.
shortcode_exists() ----------Checks if the specified shortcode is registered.
in_category() ----------Checks if the post are in a category.
in_the_loop() ----------Checks if we are inside a WP Loop.
is_main_query() ----------Checks if we are in the main WP Loop.
is_active_sidebar() ----------Checks if there is at least one widget in the widgets area.
is_child_theme() ----------Checks if a child theme being used.
is_dynamic_sidebar() ----------Checks if theme sidebars are enabled and they has at least one widget.
is_local_attachment() ----------Checks if the given URL is an attachment page.
is_multisite() ----------Checks if the multisite mode is turned on.
is_new_day() ----------Checks if the current date differs from the previous (in the loop).
is_post_type_hierarchical() ----------Checks if the post type is hierarchical (tree-like).
is_taxonomy_hierarchical() ----------Checks if the taxonomy is hierarchical (tree-like).
is_sticky() ----------Checks if the post is sticky (be shown on front page).
pings_open() ----------Checks if the post is allowed to receive pings.
post_exists() ----------Checks if there is a post with a specified title (post_title).
taxonomy_exists() ----------Checks if the specified taxonomy exist.
post_password_required() ----------Checks if the post is password protected and it is correct.
term_exists() ----------Checks if the taxonomy element exist (return the term ID).
cat_is_ancestor_of() ----------Checks if the category is child of another one (all nesting levels).
term_is_ancestor_of() ----------Checks if the term is child of another one (all nesting levels).
wp_attachment_is() ----------Checks if the attachment is an image, audio or video.
wp_attachment_is_image() ----------Checks if the attachment (post) is a image .
is_header_video_active() ----------Checks if the header video should be shown on the page.
has_custom_header() ----------Checks if the picture/video is set for the theme header.
wp_is_mobile() ----------Checks if the site is viewed on a mobile device.
wp_is_post_autosave() ----------Checks if the post is an auto-save.
wp_is_post_revision() ----------Checks if the post is a revision.
