ZCARD
Syntax
Section titled “Syntax”ZCARD keyZCARD returns the cardinality of the sorted set stored at key.
The command returns 0 if key does not exist.
Examples
Section titled “Examples”locahost:7379> ZADD users 1 alice 2 bob 3 charlieOK 3locahost:7379> ZCARD usersOK 3localhost:7379> ZCARD nonexistent_keyOK 0