ZRANK key member

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.

@return

• 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.

@examples

redis> ZADD myzset 1 "one"
TBD
redis> ZADD myzset 2 "two"
TBD
redis> ZADD myzset 3 "three"
TBD
redis> ZRANK myzset "three"
TBD
redis> ZRANK myzset "four"