Char Array vs String: which is better for storing a set of letters

Question

I need to store in a constant class 4 letter of a code. I can do:

static final String CODE_LETTERS = "TRWAG";

or

static final char[] CODE_LETTERS = {'T', 'R', 'W', 'A', 'G'};

After, I can obtain one of that characters in two ways:

final char codeLetter = CODE_LETTERS.charAt(index);

or

final char codeLetter = CODE_LETTERS[index];

what is the best way?. Please take in mind correction, performance, etc.

Answer 1

Neither is incorrect, but since you're going to be dealing with the chars individually I'd personally use the char []. That said, the impact this will have on performance is going to be negligible if even measurable.