SADD key member [member ...]

Available since 1.0.0.

Time complexity: O(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments.

Add the specified members to the set stored at key. Specified members that are already a member of this set are ignored. If key does not exist, a new set is created before adding the specified members.

An error is returned when the value stored at key is not a set.

*Return value

Integer reply: the number of elements that were added to the set, not including all the elements already present into the set.

*History

  • >= 2.4: Accepts multiple member arguments. Redis versions before 2.4 are only able to add a single member per call.

*Examples

redis>  SADD myset "Hello" 
(integer) 1
redis>  SADD myset "World" 
(integer) 1
redis>  SADD myset "World" 
(integer) 0
redis>  SMEMBERS myset 
1) "Hello"
2) "World"
redis>