Redis Srandmember Command

Redis Set

The Redis Srandmember command is used to return a random element from a set.

Starting from Redis version 2.6, the Srandmember command accepts an optional count parameter:

  • If count is positive and less than the set cardinality, the command returns an array containing count elements, and the elements in the array are all distinct. If count is greater than or equal to the set cardinality, the entire set is returned.
  • If count is negative, the command returns an array, and the elements in the array may appear repeatedly, while the length of the array is the absolute value of count.

This operation is similar to SPOP, but SPOP removes and returns a random element from the set, whereas Srandmember only returns a random element without making any changes to the set.

Syntax

The basic syntax of the Redis Srandmember command is as follows:

redis 127.0.0.1:6379> SRANDMEMBER KEY [count]

Available Versions

>= 1.0.0

Return Value

When only the set key parameter is provided, an element is returned; if the set is empty, nil is returned. If the count parameter is provided, an array is returned; if the set is empty, an empty array is returned.

Examples

redis 127.0.0.1:6379> SADD myset1 "hello"
(integer) 1
redis 127.0.0.1:6379> SADD myset1 "world"
(integer) 1
redis 127.0.0.1:6379> SADD myset1 "bar"
(integer) 1
redis 127.0.0.1:6379> SRANDMEMBER myset1
"bar"
redis 127.0.0.1:6379> SRANDMEMBER myset1 2
1) "Hello"
2) "world"

Redis Set

Other Extensions