How to convert a letter to an another letter in Java

Question

I am trying to convert a letter to another letter in Java with a simple encryption program that would convert every letter for one place down the alphabetical scale, with the exception of the letter A (the value of A would be: "(0-1)"). So letter B would turn into A, letter C would turn into B, letter R would turn into Q and so on.

Example: I love fish would become H knud ehrg

I think you should see here http://stackoverflow.com/questions/19108737/java-how-to-implement-a-shift-cipher-caesar-cipher — E. Quku, Jun 04 '16 at 15:44
Thank you for answering so quick! I will make sure to check out the code provided and thank you once again, I really appreciate it! — Fish_In_A_Suit, Jun 04 '16 at 15:47
For 'A', just complete a cycle and assign it to Z, otherwise you will have problems when decrypting. — Savvas Parastatidis, Jun 04 '16 at 15:48

ck1 · Accepted Answer · 2016-06-04T15:53:42.513

You could use something like the following algorithm to accomplish this:

// Our input string.
String input = "I love fish";

// Contains the "encrypted" output string.
StringBuilder encrypted = new StringBuilder();

// Process each character in the input string.
for (char c : input.toCharArray()) {
    if (Character.toLowerCase(c) != 'a' && Character.isLetter(c)) {
        // If the character is a letter that's not 'a', convert it to the previous letter.
        char previous = (char) ((int) c - 1);
        encrypted.append(previous);
    } else {
        // Otherwise just append the original character.
        encrypted.append(c);
    }
}

// Prints the output to stdout.
System.out.println(encrypted.toString());

How to convert a letter to an another letter in Java

1 Answers1

Linked