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

Performance is irrelevant in this case. If it’s really supposed to be constant, you can’t use the char[] approach. Consider:

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

  public static void main(String[] args) throws Exception
  {
    System.out.println(CODE_LETTERS[0]); // T
    CODE_LETTERS[0] = 'x';
    System.out.println(CODE_LETTERS[0]); // x
  }
}