What is the output of this code? import java. util. hashset; class a { public static void main(string[ ] args) { hashset set = new hashset(); set. add("a"); set. add("b"); set. add("c"); system. out. println(set.; } }

The code will give an error that is "At least one public class is required in main file".

Explanation:

In the given code if we do not use the public access modifier to the class. It will give an error so, the correct code to this question as follows:

Program:

import java.util.HashSet; //import package

public class A  //define class as public.

{

   public static void main(String[ ] args) //define main method.

   {

       HashSet set = new HashSet(); //creating hashset object.

       set.add("A"); //add alphabet in hashset

       set.add("B"); //add alphabet in hashset

       set.add("C"); //add alphabet in hashset

       System.out.print("Size of HashSet is :"set.size()); //print the size of hashset.

   }

}

Output:

Size of HashSet is : 3

Explanation of the program: