We would like to know how to count Chars in a String.
import java.util.Map; import java.util.TreeMap; /*w w w . j a v a 2s.c o m*/ public class Main{ public static void main(String[] args) { String yourString = "UNDERSTAND"; Map<Character, Integer> count = new TreeMap<Character, Integer>(); for (char c : yourString.toCharArray()) { if (count.containsKey(c)) { count.put(c, (int) count.get(c) + 1); } else { count.put(c, 1); } } System.out.println(count); } }