HashSet Basics in Java: Explanation & Practice

Problem summary

Create a HashSet and demonstrate that it prevents duplicates.

Starter code

import java.util.*;

public class Main {
    public static void main(String[] args) {
        // Create HashSet
        // Try to add: 1, 2, 2, 3, 3, 3
        // Print size and elements
    }
}

Expected output and test cases

• Unique elements only

  Size: 3
  1 2 3

Hints

1. HashSet automatically removes duplicates
2. add() returns false for duplicates
3. Order may not be preserved

Related Collections exercises

• Practice ArrayList Basics in Java
• Practice HashMap Basics in Java
• Practice List Iteration Methods in Java

Practice all Collections exercises · Run this idea in the Java compiler