ZCOUNT key min max

Available since 2.0.0.

Time complexity: O(log(N)) with N being the number of elements in the sorted set.

Returns the number of elements in the sorted set at key with a score between min and max.

The min and max arguments have the same semantic as described for ZRANGEBYSCORE.

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 value

Integer reply: the number of elements in the specified score range.

*Examples

redis> ZADD myzset 1 "one" 

  1. (integer) 1

redis> ZADD myzset 2 "two" 

  1. (integer) 1

redis> ZADD myzset 3 "three" 

  1. (integer) 1

redis> ZCOUNT myzset -inf +inf 

  1. (integer) 3

redis> ZCOUNT myzset (1 3 

  1. (integer) 2
redis>