Available in: Redis Stack
Time complexity: O(k), where k is the number of sub-filters
Returns the number of times an item may be in the filter. Because this is a probabilistic data structure, this may not necessarily be accurate.
If you just want to know if an item exists in the filter, use
it is more efficient for that purpose.
Integer reply - with the count of possible matching copies of the item in the filter.
redis> CF.COUNT cf item1 (integer) 42
redis> CF.COUNT cf item_new (integer) 0