lindex.3valkey - Man Page
Returns an element from a list by its index.
Synopsis
LINDEX
key index
Description
Returns the element at index index
in the list stored at key
. The index is zero-based, so 0
means the first element, 1
the second element and so on. Negative indices can be used to designate elements starting at the tail of the list. Here, -1
means the last element, -2
means the penultimate and so forth.
When the value at key
is not a list, an error is returned.
Reply
Resp2
One of the following:
- valkey-protocol(7) Nil reply: when index is out of range.
- valkey-protocol(7) Bulk string reply: the requested element.
Resp3
One of the following:
- valkey-protocol(7) Null reply: when index is out of range.
- valkey-protocol(7) Bulk string reply: the requested element.
Complexity
O(N) where N is the number of elements to traverse to get to the element at index. This makes asking for the first or the last element of the list O(1).
Acl Categories
@list @read @slow
History
- Available since: 1.0.0
Examples
127.0.0.1:6379> LPUSH mylist "World" (integer) 1 127.0.0.1:6379> LPUSH mylist "Hello" (integer) 2 127.0.0.1:6379> LINDEX mylist 0 "Hello" 127.0.0.1:6379> LINDEX mylist -1 "World" 127.0.0.1:6379> LINDEX mylist 3 (nil)
See Also
blmove(3valkey), blmpop(3valkey), blpop(3valkey), brpop(3valkey), linsert(3valkey), llen(3valkey), lmove(3valkey), lmpop(3valkey), lpop(3valkey), lpos(3valkey), lpush(3valkey), lpushx(3valkey), lrange(3valkey), lrem(3valkey), lset(3valkey), ltrim(3valkey), rpop(3valkey), rpush(3valkey), rpushx(3valkey)