ZCOUNT

Syntax

  1. ZCOUNT key min max

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

ACL categories: @read, @sortedset, @fast

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

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

Examples

  1. dragonfly> ZADD myzset 1 "one"
  2. (integer) 1
  3. dragonfly> ZADD myzset 2 "two"
  4. (integer) 1
  5. dragonfly> ZADD myzset 3 "three"
  6. (integer) 1
  7. dragonfly> ZCOUNT myzset -inf +inf
  8. (integer) 3
  9. dragonfly> ZCOUNT myzset (1 3
  10. (integer) 2