Creating a set of characters

Question

This seems simple, but it is really bothering me because it is not working. How do I make a simple set of characters. For example: I would like to make a set called "operators" and i would like it to include '-', '+', '*', '%', etc. I will also have a set of "digits" which would be '0' - '9'.
That way, when analyzing a string, I will be able to pick apart each character and figure out which set it belongs to.
Any help would be greatly appreciated.

Answer 1

Something like this might do it (if I'm reading your question correctly)
class CharacterSet
  public static void main(String args[])
    String operators = "%+-*/";
    String numbers = "0123456789";
    String letters = "abcdefghijklmnopqrstuvwxyz";
    String capitals = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    String test = "A+ 4 u";  
    for(int i = 0; i < test.length(); i++)
      if(operators.indexOf(test.charAt(i)) > -1) System.out.println("operator");
      else if(numbers.indexOf(test.charAt(i)) > -1) System.out.println("number");
      else if(letters.indexOf(test.charAt(i)) > -1) System.out.println("letter");
      else if(capitals.indexOf(test.charAt(i)) > -1) System.out.println("capital");
    System.exit(0);
}