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

public class IterateOverHashSetExample {
    public static void main(String[] args) {
        Set<String> programmingLanguages = new HashSet<>();
        programmingLanguages.add("C");
        programmingLanguages.add("C++");
        programmingLanguages.add("Java");
        programmingLanguages.add("Python");
        programmingLanguages.add("PHP");
        programmingLanguages.add("Ruby");

        System.out.println("=== Iterate over a HashSet using Java 8 forEach and lambda ===");
        programmingLanguages.forEach(programmingLanguage -> {
            System.out.println(programmingLanguage);
        });

        System.out.println("=== Iterate over a HashSet using iterator() ===");
        Iterator<String> programmingLanguageIterator = programmingLanguages.iterator();
        while (programmingLanguageIterator.hasNext()) {
            String programmingLanguage = programmingLanguageIterator.next();
            System.out.println(programmingLanguage);
        }

        System.out.println("=== Iterate over a HashSet using iterator() and Java 8 forEachRemaining() method ===");
        programmingLanguageIterator = programmingLanguages.iterator();
        programmingLanguageIterator.forEachRemaining(programmingLanguage -> {
            System.out.println(programmingLanguage);
        });

        System.out.println("=== Iterate over a HashSet using simple for-each loop ===");
        for(String programmingLanguage: programmingLanguages) {
            System.out.println(programmingLanguage);
        }
    }
}