Redis Srandmember Command

Redis Sets (Set)

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

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

• If count is a positive number and less than the cardinality of the set, the command returns an array containing count elements, and the elements in the array are different. If count is greater than or equal to the cardinality of the set, the entire set is returned.
• If count is negative, the command returns an array, and the elements in the array may appear multiple times, and the length of the array is the absolute value of count.

This operation is similar to SPOP, but SPOP removes a random element from the set and returns it, while 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 Version

>= 1.0.0

Return Value

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.

Online 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 Sets (Set)