SPOP key [count]

Removes and returns one or more random members from the set value store at key.

This operation is similar to SRANDMEMBER, that returns one or more random elements from a set but does not remove it.

By default, the command pops a single member from the set. When provided with the optional count argument, the reply will consist of up to count members, depending on the set’s cardinality.

@return

When called without the count argument:

@bulk-string-reply: the removed member, or nil when key does not exist.

When called with the count argument:

@array-reply: the removed members, or an empty array when key does not exist.

@examples

redis> SADD myset "one"
TBD
redis> SADD myset "two"
TBD
redis> SADD myset "three"
TBD
redis> SPOP myset
TBD
redis> SMEMBERS myset
TBD
redis> SADD myset "four"
TBD
redis> SADD myset "five"
TBD
redis> SPOP myset 3
TBD
redis> SMEMBERS myset

Note that this command is not suitable when you need a guaranteed uniform distribution of the returned elements. For more information about the algorithms used for SPOP, look up both the Knuth sampling and Floyd sampling algorithms.

History

• Starting with Redis version 3.2.0: Added the count argument.