LREM
Syntax
LREM key count element
Time complexity: O(N+M) where N is the length of the list and M is the number of elements removed.
Removes the first count
occurrences of elements equal to element
from the list
stored at key
.
The count
argument influences the operation in the following ways:
count > 0
: Remove elements equal toelement
moving from head to tail.count < 0
: Remove elements equal toelement
moving from tail to head.count = 0
: Remove all elements equal toelement
.
For example, LREM list -2 "hello"
will remove the last two occurrences of
"hello"
in the list stored at list
.
Note that non-existing keys are treated like empty lists, so when key
does not
exist, the command will always return 0
.
Return
Integer reply: the number of removed elements.
Examples
dragonfly> RPUSH mylist "hello"
(integer) 1
dragonfly> RPUSH mylist "hello"
(integer) 2
dragonfly> RPUSH mylist "foo"
(integer) 3
dragonfly> RPUSH mylist "hello"
(integer) 4
dragonfly> LREM mylist -2 "hello"
(integer) 2
dragonfly> LRANGE mylist 0 -1
1) "hello"
2) "foo"