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ZRANGE

ZRANGE key start stop [WITHSCORES]

Available since 1.2.0.

Time complexity: O(log(N)+M) with N being the number of elements in the sorted set and M the number of elements returned.

Returns the specified range of elements in the sorted set stored at key. The elements are considered to be ordered from the lowest to the highest score. Lexicographical order is used for elements with equal score.

See ZREVRANGE when you need the elements ordered from highest to lowest score (and descending lexicographical order for elements with equal score).

Both start and stop are zero-based indexes, where 0 is the first element, 1 is the next element and so on. They can also be negative numbers indicating offsets from the end of the sorted set, with -1 being the last element of the sorted set, -2 the penultimate element and so on.

start and stop are inclusive ranges, so for example ZRANGE myzset 0 1 will return both the first and the second element of the sorted set.

Out of range indexes will not produce an error. If start is larger than the largest index in the sorted set, or start > stop, an empty list is returned. If stop is larger than the end of the sorted set Redis will treat it like it is the last element of the sorted set.

It is possible to pass the WITHSCORES option in order to return the scores of the elements together with the elements. The returned list will contain value1,score1,...,valueN,scoreN instead of value1,...,valueN. Client libraries are free to return a more appropriate data type (suggestion: an array with (value, score) arrays/tuples).

Return value

Array reply: list of elements in the specified range (optionally with their scores, in case the WITHSCORES option is given).

Examples

redis> ZADD myzset 1 "one" (integer) 1 redis> ZADD myzset 2 "two" (integer) 1 redis> ZADD myzset 3 "three" (integer) 1 redis> ZRANGE myzset 0 -1

1) "one"
2) "two"
3) "three"

redis> ZRANGE myzset 2 3 1) "three" redis> ZRANGE myzset -2 -1

1) "two"
2) "three"

The following example using WITHSCORES shows how the command returns always an array, but this time, populated with element_1, score_1, element_2, score_2, ..., element_N, score_N.

redis> ZRANGE myzset 0 1 WITHSCORES

1) "one"
2) "1"
3) "two"
4) "2"

© 2009–2018 Salvatore Sanfilippo
Licensed under the Creative Commons Attribution-ShareAlike License 4.0.
https://redis.io/commands/zrange