lrange.3valkey - Man Page
Returns a range of elements from a list.
Synopsis
LRANGE key start stop
Description
Returns the specified elements of the list stored at key. The offsets start and stop are zero-based indexes, with 0 being the first element of the list (the head of the list), 1 being the next element and so on.
These offsets can also be negative numbers indicating offsets starting at the end of the list. For example, -1 is the last element of the list, -2 the penultimate, and so on.
Consistency with range functions in various programming languages
Note that if you have a list of numbers from 0 to 100, LRANGE list 0 10 will return 11 elements, that is, the rightmost item is included. This may or may not be consistent with behavior of range-related functions in your programming language of choice (think Ruby’s Range.new, Array#slice or Python’s range() function).
Out-of-range indexes
Out of range indexes will not produce an error. If start is larger than the end of the list, an empty list is returned. If stop is larger than the actual end of the list, Valkey will treat it like the last element of the list.
Reply
valkey-protocol(7) Array reply: a list of elements in the specified range, or an empty array if the key doesn’t exist.
Complexity
O(S+N) where S is the distance of start offset from HEAD for small lists, from nearest end (HEAD or TAIL) for large lists; and N is the number of elements in the specified range.
Acl Categories
@list @read @slow
History
- Available since: 1.0.0
Examples
127.0.0.1:6379> RPUSH mylist "one" (integer) 1 127.0.0.1:6379> RPUSH mylist "two" (integer) 2 127.0.0.1:6379> RPUSH mylist "three" (integer) 3 127.0.0.1:6379> LRANGE mylist 0 0 1) "one" 127.0.0.1:6379> LRANGE mylist -3 2 1) "one" 2) "two" 3) "three" 127.0.0.1:6379> LRANGE mylist -100 100 1) "one" 2) "two" 3) "three" 127.0.0.1:6379> LRANGE mylist 5 10 (empty array)
See Also
blmove(3valkey), blmpop(3valkey), blpop(3valkey), brpop(3valkey), lindex(3valkey), linsert(3valkey), llen(3valkey), lmove(3valkey), lmpop(3valkey), lpop(3valkey), lpos(3valkey), lpush(3valkey), lpushx(3valkey), lrem(3valkey), lset(3valkey), ltrim(3valkey), rpop(3valkey), rpush(3valkey), rpushx(3valkey)