Question

Write a java program to add 4 different printers in a hashset. What will happen when you add duplicate elements?

Answer 1

Set is a collection which doesn't contains duplicate elements.

Java code:

import java.util.HashSet;

public class TestClass{

public static void main(String[]args){

      //HashSet

      HashSet<String> printerSet = new HashSet<String>();

      //adding 4 printers to HashSet

      printerSet.add("Laser printers");

      printerSet.add("Line printers");

      printerSet.add("Daisy-wheel printers");

      printerSet.add("Drum printer");

      //displaying the output

      System.out.println("Before adding duplicate element:");

      System.out.println("--------------------------------");

      for(String printers: printerSet){

            System.out.println(printers);

            }

      //Now adding duplicate element to the printer

      System.out.println("\nAdding duplicate element:");

      printerSet.add("Line printers");

      //again displaying the output

      System.out.println("\nAfter adding duplicate element:");

      System.out.println("--------------------------------");

      for(String printers: printerSet){

            System.out.println(printers);

            }

      }

}

Output: