ZREVRANK
Returns the rank of a member in a sorted set, with the scores ordered from high to low. The rank is 0-based, meaning that the member with the highest score has rank 0.
Syntax
ZREVRANK key member
Parameters
- key: The name of the sorted set.
- member: The member whose rank you want to determine.
Details
- Available since: 2.0.0
- Time complexity: O(log(N)) where N is the number of elements in the sorted set.
- ACL categories:
@read
,@sortedset
,@fast
The ZREVRANK
command returns the rank of a specified member in the sorted set stored at key
, with scores ordered from high to low. If the member exists in the sorted set, the command returns its rank as an integer. If the member does not exist, ZREVRANK
returns nil
.
Examples
Basic Usage
Assume we have a sorted set called myzset
with the following members:
ZADD myzset 1 "a" 2 "b" 3 "c" 4 "d" 5 "e"
To get the rank of member "c" with scores ordered from high to low:
ZREVRANK myzset "c"
This will return:
(integer) 2
Member Not Found
If you try to get the rank of a member that does not exist in the sorted set:
ZREVRANK myzset "f"
This will return:
(nil)
Edge Cases
- If the member does not exist in the sorted set,
ZREVRANK
returnsnil
. - If the key does not exist,
ZREVRANK
returnsnil
. - If the key exists but is not a sorted set, an error is returned.
RESP2/RESP3 Reply
- Integer reply: the rank of the member if it exists, or
nil
if the member does not exist.