Unschedules all events attached to the hook.
Can be useful for plugins when deactivating to clean up the cron queue.
Warning: This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. For information about casting to booleans see the PHP documentation. Use the
=== operator for testing the return value of this function.
(string) (Required) Action hook, the execution of which will be unscheduled.
(int|false) On success an integer indicating number of events unscheduled (0 indicates no events were registered on the hook), false if unscheduling fails.
|5.1.0||Return value added to indicate success or failure.|