Redis LLEN command returns the length of the list stored at the key. If the key does not exist, it is interpreted as an empty list and 0 is returned. An error is returned when the value stored at the key is not a list.
Integer reply, the length of the list at the key.
Following is the basic syntax of Redis LLEN command.
redis 127.0.0.1:6379> LLEN KEY_NAME
redis 127.0.0.1:6379> RPUSH list1 "foo" (integer) 1 redis 127.0.0.1:6379> RPUSH list1 "bar" (integer) 2 redis 127.0.0.1:6379> LLEN list1 (integer) 2