HashSet in Java - Unique Elements

HashSet

A HashSet is a collection of items where every item is unique, and it is found in the java.util package.

import java.util.HashSet;
public class Main {
  public static void main(String[] args) {
    HashSet cars = new HashSet();
    cars.add("Volvo");
    cars.add("BMW");
    cars.add("Ford");
    cars.add("BMW"); // Duplicate, won't be added
    cars.add("Mazda");
    System.out.println(cars);
    
    // Check if exists
    System.out.println(cars.contains("Mazda"));
  }
}