Question

I have a program like this

public class no_of_letters_count {
static int i;
 public static void main(String[] args) 
 {

  String sMessage="hello how r u";
  String saMessage[] = sMessage.split("");
  List sList = Arrays.asList(saMessage);                  
  Collections.sort(sList);
  Iterator i=sList.iterator();
  while (i.hasNext())
  {
   System.out.println((String)i.next());
  }
 }
}

//Now i want to count the number of occurance of each characters.

Like

Count of h=2

Count of e=1

and so on

Answer 1

Iterate over sList and put each char in a HashMap. If it doesn’t exists start with count 1, otherwise increment the count.

EDIT : Cannot help posting some code.

First of all, use gnerics.

List<Character> sList = Arrays.asList(saMessage.toCharArray()); 

Then use the following map :

Map<Character, Integer> cmap = new HashMap<Character, Integer>();