Java Collections : Set Example

Hello Friends,

This is the Example for all the methods used in the java collections SET inteface, each method is implemented in the below example.

import java.util.HashSet;
import java.util.Set;
import java.util.Iterator;

public class SetExample
{
     public static void main(String args[]) {
     //initialization
     Set nameSet1 = new HashSet();
     Set nameSet2 = new HashSet();
     // add() method
     nameSet1.add("a");
     nameSet1.add("b");
     nameSet1.add("c");

     nameSet2.add("a");
     nameSet2.add("b");
     nameSet2.add("c");
     nameSet2.add("d");

     //equals() method
     {
      //Checking Sets whether Identical or not
        if (nameSet2.equals(nameSet1) || nameSet1.containsAll(nameSet2))
        System.out.println("The sets are identical");
        else
        System.out.println("The sets are not identical");
      }

     //addAll() method
     nameSet1.addAll(nameSet2);
     System.out.println("The contents of Set2 is added in Set1");
     {
         //After adding, Checking Sets whether Identical or not
         if (nameSet2.equals(nameSet1) && nameSet1.containsAll(nameSet2))
         System.out.println("The sets are identical");
         else
         System.out.println("The sets are not identical");
     }

     //size() method
     int size = nameSet1.size();
     System.out.println("Size of Set1 is =" + size);

     //iterator() method
     Iterator it1 = (Iterator) nameSet1.iterator();
     System.out.print("The elements in Set 1 are as-");
     while (it1.hasNext())
    {
       Object element1 = it1.next();
       System.out.print(element1 + ", ");
     }

     // contains() method
     if (nameSet1.contains("a"))
        System.out.println("n" + "the set1 contains element a");
     else
        System.out.println("the set1 doesnot contains element a");

     //clear() method
      nameSet2.clear();
      System.out.println("The Set 2 is cleared");

     //hashcode()
     int hash = nameSet1.hashCode();
     System.out.println("the hashCode od set1 is "+hash);

     //isEmpty() method
     if (nameSet2.isEmpty())
        System.out.println("The Set 2 is empty");
     else
        System.out.println("The Set 2 is not empty");

    //toArray() method
    Object[] array = nameSet1.toArray();
    int len = array.length;
    System.out.println("Length of array is " + len);
    for (int i = 0; i < len; i++)
    {
        System.out.println("value at index " + i + " is " + array[i]);
     }

     //remove() method
     nameSet1.remove("d");
     System.out.print("The element d is removed from Set 1 and the remaining elements are as - ");
     Iterator it2 = (Iterator) nameSet1.iterator();
     while (it2.hasNext()) {
     Object element = it2.next();
     System.out.print(element + ", ");
    }
  }
}

Hope this will help you.

Thanks,

admin@code2java.com