How to copy one Set to another Set

In this article we are gonna see an example program to copy one Set to another Set.

Example

In this example we are copying one HashSet to another HashSet, however you can use any other Set like TreeSet, LinkedHashSet etc in the same manner as shown below.

import java.util.HashSet;
class CopySetExample{ 
  public static void main(String[] args) {
     // Create a HashSet
     HashSet<String> hset = new HashSet<String>();
 
     //add elements to HashSet
     hset.add("Element1");
     hset.add("Element2");
     hset.add("Element3");
     System.out.println("Set before addAll:"+ hset);
 
     // Create another HashSet
     HashSet<String> hset2 = new HashSet<String>();
     hset2.add("Item1");
     hset2.add("Item2");
 
     // Copying one Set to another
     hset.addAll(hset2);
 
     System.out.println("Set after addAll:"+ hset);
  }
}

Output:

Set before addAll:[Element1, Element2, Element3]
Set after addAll:[Item1, Item2, Element1, Element2, Element3]