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.
Use ZRANK to get the rank of an element with the scores ordered from low to high.
@return
member exists in the sorted set, @integer-reply: the rank of member.member does not exist in the sorted set or key does not exist, @bulk-string-reply: nil.@examples
ZADD myzset 1 "one"
ZADD myzset 2 "two"
ZADD myzset 3 "three"
ZREVRANK myzset "one"
ZREVRANK myzset "four"