Java tutorial
public class Main { public static void main(String args[]) { System.out.println(stripGarbage("A good String")); } public static String stripGarbage(String s) { String good = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; String result = ""; for (int i = 0; i < s.length(); i++) { if (good.indexOf(s.charAt(i)) >= 0) result += s.charAt(i); } return result; } }