Returns the cardinality of the set which would result from the intersection of all the given sets.
Keys that do not exist are considered to be empty sets. With one of the keys being an empty set, the resulting set is also empty (since set intersection with an empty set always results in an empty set).
Integer reply: the number of elements in the resulting intersection.
(integer) 1redis> SADD key1 "b"
(integer) 1redis> SADD key1 "c"
(integer) 1redis> SADD key2 "c"
(integer) 1redis> SADD key2 "d"
(integer) 1redis> SADD key2 "e"
(integer) 1redis> SINTER key1 key2
1) "c"redis> SINTERCARD key1 key2
ERR ERR unknown command `SINTERCARD`, with args beginning with: `bd0b2897cf7b363a0a6b6c8fa7d59e53:key1`, `bd0b2897cf7b363a0a6b6c8fa7d59e53:key2`,