ZRANK – Redis

Available since 2.0.0.

时间复杂度： O(log(N))

Returns the rank of member in the sorted set stored at key, with the scores ordered from low to high. The rank (or index) is 0-based, which means that the member with the lowest score has rank 0.

Use ZREVRANK to get the rank of an element with the scores ordered from high to low.

返回值

If member exists in the sorted set, Integer reply: the rank of member.
If member does not exist in the sorted set or key does not exist, Bulk string reply: nil.

例子

redis> ZADD myzset 1 "one"

(integer) 1

redis> ZADD myzset 2 "two"

(integer) 1

redis> ZADD myzset 3 "three"

(integer) 1

redis> ZRANK myzset "three"

(integer) 2

redis> ZRANK myzset "four"

(nil)

ZRANK key member

返回值

例子