Using WordPress ‘is_tag()’ PHP function
Determines whether the query is for an existing tag archive page.
Posts
Using WordPress ‘is_sticky()’ PHP function
Learn how to use the WordPress 'is_sticky()' PHP function to determine if a post is sticky and display different content based on that status
Using WordPress ‘is_protected_meta()’ PHP function
Learn how to use the in WordPress to determine if a meta key is protected
Using WordPress ‘is_post_status_viewable()’ PHP function
Determines whether a post status is considered “viewable”.
Using WordPress ‘is_post_publicly_viewable()’ PHP function
The `is_post_publicly_viewable()` function in WordPress returns `true` if a post is publicly viewable and `false` otherwise
Using WordPress ‘is_paged()’ PHP function
Determines whether the query is for a paged result and not for the first page.
Using WordPress ‘is_new_day()’ PHP function
Determines whether the publish date of the current post in the loop is different from the publish date of the previous post in the loop.
Using WordPress ‘is_multi_author()’ PHP function
Determines whether this site has more than one author.
Using WordPress ‘like_escape()’ PHP function
Formerly used to escape strings before searching the DB. It was poorly documented and never worked as described.