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Java program to remove all elements of HashSet collection

Java example to remove all elements of HashSet collection.
Submitted by Nidhi, on May 08, 2022

Problem statement

In this program, we will create a set using the HashSet collection to store integer elements. Then we will remove all elements of HashSet using the clear() method.

Source Code

The source code to remove all elements of the HashSet collection is given below. The given program is compiled and executed successfully.

// Java program to remove all elements of 
// HashSet collection

import java.util.*;

public class Main {
  public static void main(String[] args) {

    HashSet < Integer > nums = new HashSet();

    nums.add(1);
    nums.add(2);
    nums.add(3);
    nums.add(4);

    System.out.println("Set items: ");
    Iterator < Integer > itr = nums.iterator();
    while (itr.hasNext()) {
      System.out.println(" " + itr.next());
    }

    nums.clear();

    System.out.println("Set items: ");
    Iterator < Integer > itr1 = nums.iterator();
    while (itr1.hasNext()) {
      System.out.println(" " + itr1.next());
    }
  }
}

Output

Set items: 
 1
 2
 3
 4
Set items:

Explanation

In the above program, we imported the "java.util.*" package to use the HashSet collection. Here, we created a public class Main that contains a main() method.

The main() method is the entry point for the program. And, we created a set nums to store integer data elements using HashSet collection. Then we removed all elements from the nums HashSet. After that, we printed the updated collection.

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