original
http://redis.io/commands/zrevrank
Introduction
Determine the index of a member in a sorted set, with scores ordered from high to low.
Determines the index of the member in the sorted set, in order of highest to lowest score.
grammar
ZREVRANK key member
Version
Available since 2.0.0.
Available since version 2.0.0.
time complexity
Time complexity: O(log(N))
describe
Returns the rank of member in the sorted set stored at key, with the scores ordered from high to low. The rank (or index) is 0-based, which means that the member with the highest score has rank 0.
Returns the order of the members in the sorted set, from high to low score. The order (or index) is 0-based, meaning that the order of the highest scoring member is 0.
Use ZRANK to get the rank of an element with the scores ordered from low to high.
Use ZRANK to get the order of elements, sorted by score from low to high.
return value
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.
1) If the member exists in the sorted set, return the order of the members.
2) If the member does not exist in the sorted set, or the key does not exist, return nil.
example
redis> ZADD myzset 1 "one"
(integer) 1
redis> ZADD myzset 2 "two"
(integer) 1
redis> ZADD myzset 3 "three"
(integer) 1
redis> ZREVRANK myzset "one"
(integer) 2
redis> ZREVRANK myzset "four"
(nil)
redis>