Identify duplicate elements using HashSet and HashMap in Java

This program that you see is using HashSet and HashMap which is considered better than using 2 for loops to do the same job.

Using HashSet >> Stores unique values.

import java.util.HashSet;

import java.util.Set;

public class DuplicateElements {

  public static void main(String[] args) {

  String names[] = {"Java", "C", "C++", "Golang", "Ruby", "C"};

      Set<String> s = new HashSet<String>();

      for (String name : names) {

if (s.add(name) == false) {   System.out.println("Duplicate element:"+ name);

}

     }

   }

}

Using HashMap

import java.util.HashMap;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;

public class DuplicateElements {

public static void main(String[] args) {

String names[] = {"Java", "C", "C++", "Golang", "Ruby", "C++"};

Map<String, Integer> s = new HashMap<String, Integer>();

for (String name: names) {

Integer count = s.get(name);

if (count == null) {

s.put(name, 1);

}

else {

s.put(name, ++count);

}

}

//get values from this HashMap

Set<Entry<String, Integer>> e = s.entrySet();

for (Entry<String, Integer> entry: e) {

if (entry.getValue()>1) {

System.out.println("Duplicate Item:" + entry.getKey());

}

}

}

}