Categories (category)
| cat_is_ancestor_of() | Checks if the specified category is a child of another specified category (all nesting levels are checked). Conditional tag. |
| category_description() | Gets the description of the category, which is specified on the category editing page in the admin panel (posts > categories). |
| category_exists() | Checks if the specified category exists. If it does, it returns the ID of that category. |
| get_cat_ID() | Gets the category ID by the given name. |
| get_cat_name() | Gets the name of the category by the passed ID. |
| get_categories() | Gets categories as an array of objects. |
| get_category() | Gets data of the specified category. |
| get_category_by_slug() | Gets category data by its alternative name (slug). |
| get_category_link() | Gets the correct link to the category page by the given category ID. |
| get_category_parents() | Gets a list of parent categories of the current category. The list is displayed in hierarchical order. |
| get_the_category_by_ID() | Gets the category name by the given ID. |
| in_category() | Checks whether the current (or specified) post belongs to the specified category (multiple categories can be specified). Conditional tag. |
| single_cat_title() | Displays the title of the category or tag. Used outside the loop. Intended for archive pages. |
| wp_create_category() | Simplified function for adding a category, which requires the name of the new category and, if needed, the ID of the parent category. |
| wp_dropdown_categories() | Display or retrieve the HTML dropdown list of categories. Instead of categories you can specify the name of an custom taxonomy. |
| wp_insert_category() | Inserts a new category into the database. Or updates an existing category by specifying a category ID. |
| wp_list_categories() | Displays a list of categories as HTML links. If you click on the link, all posts from the category will be shown. |