LPUSHX

Available since 2.2.0.

Time complexity: O(1)

Inserts value 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.

*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)

LPUSHX key value

*Return value

*Examples