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ZPOPMAX

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ZPOPMAX key [count]
Group
Sorted set
Complexity
O(log(N)*M) where N is the size of the sorted set and M is the number of members popped
Arity
-2 (at least 2 words, counting the command name)
Flags
write, fast
Keys
first 1, last 1, step 1
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ZPOPMAX removes and returns the member with the highest score from the sorted set at key, together with its score. With count, it removes and returns up to count members, highest score first. When the sorted set becomes empty, the key is deleted.

To wait for a member when the set is empty, use BZPOPMAX.

Return value

Section titled “Return value”
Case RESP2 RESP3
No count Two-element array: member, score (bulk string) Two-element array: member, score (double)
With count Flat array: member, score, member, score, … Array of two-element arrays: [member, score], the score a double
Key does not exist, or count is 0 Empty array Empty array

Errors:

  • ERR value is out of range, must be positive if count is negative or not an integer. This is checked before the key is looked up.
  • ERR syntax error if more than one count argument is given.
  • WRONGTYPE if key holds a value that is not a sorted set.

Examples

Section titled “Examples”
127.0.0.1:6379> ZADD board 1 "a" 2 "b" 3 "c"
(integer) 3
127.0.0.1:6379> ZPOPMAX board
1) "c"
2) "3"
127.0.0.1:6379> ZPOPMAX board 2
1) "b"
2) "2"
3) "a"
4) "1"

With RESP3 (redis-cli -3) and a count, each pair is nested:

127.0.0.1:6379> ZADD board 1 "a" 2 "b"
(integer) 2
127.0.0.1:6379> ZPOPMAX board 2
1) 1) "b"
   2) (double) 2
2) 1) "a"
   2) (double) 1

Compatibility

Section titled “Compatibility”

Same as Redis 7.4 and Valkey 8.

See also

Section titled “See also”

ZPOPMIN, BZPOPMAX, ZMPOP, ZREVRANGE