title: find duplicate words in java array and return array with unique duplicate words - use method
body: <p>I am new to java, and am confused with the problem.
  This is what I came up so far. 
  I am still working on it, if I come up with any progress, I'll post it here.</p>
  
  <pre><code>public class charArray {
  
  public static void main(String[] args) {
  
      String[] strArray = new String[] {"apple", "ball", "cat", "apple", "ball", "apple"};
      //output should be ["apple", "ball"]
  
      checkDuplicate(strArray);
  }
  public static String[] checkDuplicate(String[] strArray){
      String[] newArray = new String[]{};
      for(int i = 0; i &lt; strArray.length; i++){
  
          for(int j = 0; j &lt; i; j++){
              if (strArray[i].equals(srtArray[j])){
                  newArray = strArray[i];
              }
          }
  
      }
      return newArray[];
  
  }
  </code></pre>
  
  <p>}</p>
  
  <hr>
  
  <p>New progress:
  Ok, my mediocre head has gone this far: (and the solution works)
  It prints out the unique array of Duplicate elements.
  But now I need to implement the same code, by calling a method.
  Any help is appreciated.</p>
  
  <pre><code>import java.util.*;
  
  public class setChar {
  
  public static void main(String[] args) {
      String[] strArray = new String[] {"apple", "ball", "cat", "apple", "ball", "apple"};
      Set set = new HashSet();
      Set uniqueSet = new HashSet();
      for(int i = 0; i &lt; strArray.length ; i++ ){
          boolean b = set.add(strArray[i]);
          if(b == false){
              uniqueSet.add(strArray[i]);
          }
      }
      Iterator it = uniqueSet.iterator();
      while (it.hasNext()){
          System.out.println(it.next());
      }
  }
  
  }
  </code></pre>
  
  <p>The output is: 
  <strong>ball
  apple</strong></p>
  
  <hr>
  
  <p>Finally implemented with method, with proper return type.
  Please let me know, if this can be further optimized.
  Thank all for you suggestions. Here is the working code:</p>
  
  <pre><code>public class retUnique {
  
  public static void main(String[] args) {
      String[] strArray = new String[] {"apple", "ball", "cat", "apple", "ball", "apple"};
  
      System.out.println(printUnique(strArray));
  }
  
  public static Set&lt;String&gt; printUnique(String[] strArray){
      Set&lt;String&gt; set = new HashSet&lt;String&gt;();
      Set&lt;String&gt; uniqueSet = new HashSet&lt;String&gt;();
      for(int i = 0; i &lt; strArray.length ; i++ ){
          boolean b = set.add(strArray[i]);
          if(b == false){
              uniqueSet.add(strArray[i]);
          }
      }
      return(uniqueSet);
  }
  
  }
  </code></pre>