redis commands sets srandmember

SRANDMEMBER

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Get a random member from a set

Usage is srandmember key.
SPOP retrieves and deletes the data; this command only retrieves it.

count is available since version 2.6

Usage is srandmember key count.
If count is positive, members are returned without duplicates.
If count is negative, members may be returned with duplicates.
This is like drawing balls from a bag.
For example, when count is 2, two balls are drawn; if A was drawn first, the next one is drawn from B, C, D.
When count is -2, two balls are drawn; if A was drawn first, A is put back in the bag and the next one is drawn from A, B, C, D.
Therefore A,A can be returned.

When count is greater than the number of members

If count is positive, it returns as many members as exist.
If count is negative, it returns count members, allowing duplicates.

Syntax

SRANDMEMBER key [count]

• Available since version 1.0.0.
• Time complexity is O(N). N is the count.
• count is available since version 2.6.