SDIFF – Redis

始于1.0.0可用。

时间复杂度： O(N) where N is the total number of elements in all given sets.

Returns the members of the set resulting from the difference between the first set and all the successive sets.

For example:

key1 = {a,b,c,d}
key2 = {c}
key3 = {a,c,e}
SDIFF key1 key2 key3 = {b,d}

Keys that do not exist are considered to be empty sets.

返回值

Array reply: list with members of the resulting set.

redis> SADD key1 "a"

(integer) 1

redis> SADD key1 "b"

(integer) 1

redis> SADD key1 "c"

(integer) 1

redis> SADD key2 "c"

(integer) 1

redis> SADD key2 "d"

(integer) 1

redis> SADD key2 "e"

(integer) 1

redis> SDIFF key1 key2

1) "a"
2) "b"