- Usage:
-
LINSERT key 〈 BEFORE | AFTER 〉 pivot element
- Complexity:
- O(N) where N is the number of elements to traverse before seeing the value pivot. This means that inserting somewhere on the left end on the list (head) can be considered O(1) and inserting somewhere on the right end (tail) is O(N).
- Since:
- 2.2.0
- ACL Categories:
- @list, @write, @slow
-
Integer reply: the list length after a successful insert operation.
-
Integer reply:
0when the key doesn't exist. -
Integer reply:
-1when the pivot wasn't found.
Inserts element in the list stored at key either before or after the reference
value pivot.
When key does not exist, it is considered an empty list and no operation is
performed.
An error is returned when key exists but does not hold a list value.
Examples
127.0.0.1:6379> RPUSH mylist "Hello"
(integer) 1
127.0.0.1:6379> RPUSH mylist "World"
(integer) 2
127.0.0.1:6379> LINSERT mylist BEFORE "World" "There"
(integer) 3
127.0.0.1:6379> LRANGE mylist 0 -1
1) "Hello"
2) "There"
3) "World"
RESP2/RESP3 Reply
One of the following: