LPUSHX key element [element ...]

Available since 2.2.0.

Time complexity: O(1) for each element added, so O(N) to add N elements when the command is called with multiple arguments.

Inserts specified values at the head of the list stored at key, only if key already exists and holds a list. In contrary to LPUSH, no operation will be performed when key does not yet exist.

*Return value

Integer reply: the length of the list after the push operation.

*History

  • >= 4.0: Accepts multiple element arguments. In Redis versions older than 4.0 it was possible to push a single value per command.

*Examples

redis>  LPUSH mylist "World" 
(integer) 1
redis>  LPUSHX mylist "Hello" 
(integer) 2
redis>  LPUSHX myotherlist "Hello" 
(integer) 0
redis>  LRANGE mylist 0 -1 
1) "Hello"
2) "World"
redis>  LRANGE myotherlist 0 -1 
(empty list or set)
redis>