Checks (category)
| array_is_list() | Checks if an array is a list. |
| is_admin_bar_showing() | Checks whether the "Admin bar" (toolbar) will be shown (or has already been shown). That is, whether the admin panel will be displayed for the current user. Conditional tag. |
| is_blog_installed() | Checks if the site is installed. It checks for the presence of the |
| is_countable() | Checks if the content of the variable is a countable value (array or an instance of Countable|SimpleXMLElement|ResourceBundle). |
| is_email() | Checks if the given string is an e-mail address. |
| is_iterable() | Checks whether the contents of the variable match the pseudo-type |
| is_php_version_compatible() | Compares the provided PHP version with the PHP version installed on the server. |
| is_serialized() | Check the given value if it's a serialized string. |
| is_serialized_string() | Checks if a string is serialized in the specified serialized string. That is, whether the string (and not an array or number) was serialized. |
| is_wp_error() | Checks whether the passed variable is a WordPress Error. |
| is_wp_version_compatible() | Compares the provided version of WordPress with the installed version of WordPress. |
| seems_utf8() | Checks to see if a string is UTF-8 encoded. |
| wp_doing_ajax() | Determines whether the current request is a WordPress Ajax request. |
| wp_is_https_supported() | Checks if the domain and server support the HTTPS protocol. |
| wp_is_json_request() | Checks if the current request is a JSON request or expects a JSON response. |
| wp_is_numeric_array() | Checks if the specified variable is an numeric-indexed array. |
| wp_is_using_https() | Checks if the site is using HTTPS. |
| wp_validate_boolean() | Converts the value of the specified variable to boolean true or false. |