I want to cipher a message from the user using the cipher key.
the user should enter the message .
Then he should enter the key like a number from 1 to 26 . The method should then transfer each letter into another letter using the ascii code. For example if the letter is A and the key is 3 , the letter after ciphering the messge will be D
most important that I have 2 classes one is Listnode has "char data "and "Listnode* next".
The other class is a class that contain this method and it has members like tail and head. which are pointers from the first class (Listnode).

My real issue is that i can't understand how to store data using pointers
It sounds to me like you are doing a caesar cipher using a linked list.

A linked list is something like this

struct Node
    T data; //T is the type of data
    Node *next;

Check out this article:

Also for ciphering this topic comes up very often and it is a very interesting one but maybe check out these videos:
Topic archived. No new replies allowed.