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" 

  1. (integer) 1

redis> LPUSHX mylist "Hello" 

  1. (integer) 2

redis> LPUSHX myotherlist "Hello" 

  1. (integer) 0

redis> LRANGE mylist 0 -1 

  1. 1) "Hello"
  2. 2) "World"

redis> LRANGE myotherlist 0 -1 

  1. (empty list or set)
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