When all the elements in a sorted set are inserted with the same score, in order to force lexicographical ordering, this command returns the number of elements in the sorted set at key with a value between min and max.
The min and max arguments have the same meaning as described for
ZRANGEBYLEX.
Note: the command has a complexity of just O(log(N)) because it uses elements ranks (see ZRANK) to get an idea of the range. Because of this there is no need to do a work proportional to the size of the range.
@return
@integer-reply: the number of elements in the specified score range.
@examples
ZADD myzset 0 a 0 b 0 c 0 d 0 e
ZADD myzset 0 f 0 g
ZLEXCOUNT myzset - +
ZLEXCOUNT myzset [b [f