Main.java Source code

Introduction

Here is the source code for Main.java

Source

import java.util.HashSet;
import java.util.Set;

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

        Set<String> s1 = new HashSet<>();

        // Add a few elements
        s1.add("HTML");
        s1.add("CSS");
        s1.add("XML");
        s1.add("XML"); // Duplicate

        // Create another set by copying s1
        Set<String> s2 = new HashSet<>(s1);
        // Add a few more elements 
        s2.add("Java");
        s2.add("SQL");
        s2.add(null); // one null is fine
        s2.add(null); // Duplicate

        System.out.println("s1: " + s1);
        System.out.println("s1.size(): " + s1.size());

        System.out.println("s2: " + s2);
        System.out.println("s2.size(): " + s2.size());
    }
}