Optional blockingOptional dataUsed for "database" commands to enforce type checking.
Private loggerMaximum number of parameters allowed. -1 for no maximum.
Minimum number of parameters require.
Optional pubUsed when PUB/SUB is in effect.
Optional signSign is used in commands with a compliment command. The only current example is INCR/DECR. Sign is 1 for INCR and -1 for DECR
Optional txUsed in transactions to enqueue a command.
Every command must implement the execute method.
Available since 1.2.0.
ZCARD key
Returns the sorted set cardinality (number of elements) of the sorted set stored at key.
Return value
Integer reply: the cardinality (number of elements) of the sorted set, or 0 if key does not exist.