Java Program To Find Duplicate Characters In String

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import java.util.HashMap;
import java.util.Set;

public class JavaStringDuplicateCharacter {

	static void duplicateCharCount(String inputString) {

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

		char[] strArray = inputString.toCharArray();

		for (char c : strArray) {
			if (charCountMap.containsKey(c)) {
				charCountMap.put(c, charCountMap.get(c) + 1);
			} else {

				charCountMap.put(c, 1);
			}
		}

		Set<Character> charsInString = charCountMap.keySet();

		System.out.println("Duplicate Characters In " + inputString);

		for (Character ch : charsInString) {
			if (charCountMap.get(ch) > 1) {
				System.out.println(ch + " : " + charCountMap.get(ch));
			}
		}
	}

	public static void main(String[] args) {
		duplicateCharCount("Java Scan");

		duplicateCharCount("Hello welcome");

		duplicateCharCount("Your Heart");
	}
}
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