How to count frequency of characters in a string?

Question

How to count the frequency of characters in a string in Java?

Answer 1

You can try something like this:
 

HashMap<Character, Integer> map = new HashMap<Character, Integer>();

String s = "aasjjikkk";

for (int i = 0; i < s.length(); i++) {

    char c = s.charAt(i);

    Integer val = map.get(c);

    if (val != null) {

        map.put(c, new Integer(val + 1));

    }

    else {

       map.put(c, 1);

   }

}

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