LINDEX

Syntax

  1. LINDEX key index

Time 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: @read, @list, @slow

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.

Return

Bulk string reply: the requested element, or nil when index is out of range.

Examples

  1. dragonfly> LPUSH mylist "World"
  2. (integer) 1
  3. dragonfly> LPUSH mylist "Hello"
  4. (integer) 2
  5. dragonfly> LINDEX mylist 0
  6. "Hello"
  7. dragonfly> LINDEX mylist -1
  8. "World"
  9. dragonfly> LINDEX mylist 3
  10. (nil)