How do I increment a variable to the next or previous letter in the alphabet?

Question

I have a capital letter defined in a variable string, and I want to output the next and previous letters in the alphabet. For example, if the variable was equal to \'C\'

Answer 1

If you are limited to the latin alphabet, you can use the fact that the characters in the ASCII table are ordered alphabetically, so:

System.out.println((char) ('C' + 1));
System.out.println((char) ('C' - 1));

outputs D and B.

What you do is add a char and an int, thus effectively adding the int to the ascii code of the char. When you cast back to char, the ascii code is converted to a character.