package in.bench.resources.java.collections;

import java.util.HashSet;

public class DeleteAndDeleteAllElementsOfHashSet {

	public static void main(String[] args) {

		// creating HashSet object of type String
		HashSet<String> hs = new HashSet<String>();

		// adding elements to HashSet object - 8
		hs.add("Sundar Pichai");
		hs.add("Satya Nadella");
		hs.add("Shiv Nadar");
		hs.add("Shantanu Narayen");
		hs.add("Sundar Pichai"); // duplicate object
		hs.add("Francisco D’Souza");
		hs.add(null); // one null is allowed
		hs.add(null); // Again, null is allowed - duplicate

		System.out.println("Size of an HashSet is : "
				+ hs.size());

		// Iterating using enhanced for-loop
		System.out.println("\nIterating using enhanced for-loop\n");
		for(String founder : hs) {
			System.out.println(founder);
		}

		// deleting particular element
		hs.remove("Shiv Nadar");
		System.out.println("\n\nHashSet size after deleting : "
				+ hs.size());

		// Iterating using enhanced for-loop
		System.out.println("\nAfter deleting particular object\n");
		for(String founder : hs) {
			System.out.println(founder);
		}

		// deleting all elements
		hs.clear();
		System.out.println("\n\nHashSet size after clearing : "
				+ hs.size());

		// Iterating using enhanced for-loop
		System.out.println("\nIterating after clearing \n" + hs);
	}
}

Size of an HashSet is : 6

Iterating HashSet using enhanced for-loop

null
Shantanu Narayen
Francisco D’Souza
Shiv Nadar
Satya Nadella
Sundar Pichai

HashSet size after deleting : 5

Iterating after deleting particular object

null
Shantanu Narayen
Francisco D’Souza
Satya Nadella
Sundar Pichai

HashSet size after clearing : 0

Iterating after clearing
[]