11 Appendix More List Operation Commands #

Insert an element before/after a certain value #

Syntax: linsert key before|after pivot value Example:

127.0.0.1:6379> linsert list3 before b A
(integer) 4
127.0.0.1:6379> lrange list3 0 -1
"a"
"A"
"b"
"c"

Modify an element by index #

Syntax: lset key index value Example:

127.0.0.1:6379> lindex list3 0
"a"
127.0.0.1:6379> lset list3 0 A
OK
127.0.0.1:6379> lindex list3 0
"A"

Delete an element by index #

Syntax: ltrim key start stop Example:

127.0.0.1:6379> lpush list a b c
(integer) 3
127.0.0.1:6379> ltrim list 0 1
OK
127.0.0.1:6379> lrange list 0 -1
1) "c"
2) "b"

Query the length of a list #

Syntax: llen key Example:

127.0.0.1:6379> llen list
(integer) 2

Delete a specified number of elements #

Syntax: lrem key count value Example:

127.0.0.1:6379> lpush list a a b b c c
(integer) 6
127.0.0.1:6379> lrem list 2 a
(integer) 2
127.0.0.1:6379> lrem list 1 b
(integer) 1
127.0.0.1:6379> lrange list 0 -1
1) "c"
2) "c"
3) "b"