Get Size of Java HashSet Example

This Java Example shows how to get the size or nubmer of elements stored in Java HashSet object using size method.

import java.util.HashSet;

public class GetSizeOfJavaHashSetExample {

 public static void main(String[] args) {

  // create HashSet object
  HashSet hSet = new HashSet();

  /**
   * To get the size of HashSet use int size() method of HashSet class. It
   * returns the number of elements stored in HashSet object.
   **/
  System.out.println("Size of HashSet : " + hSet.size());

  // add elements to HashSet object
  hSet.add(new Integer("1"));
  hSet.add(new Integer("2"));
  hSet.add(new Integer("3"));

  System.out.println("Size of HashSet after addition : " + hSet.size());

  // remove one element from HashSet using remove method
  hSet.remove(new Integer("1"));
  System.out.println("Size of HashSet after removal : " + hSet.size());
 }
}

The output is:



Size of HashSet : 0
Size of HashSet after addition : 3
Size of HashSet after removal : 2