Output of Java programs | Set 13 (Collections)

import java.util.*;

public class priorityQueue {
    public static void main(String[] args)
    {
        PriorityQueue<Integer> queue
            = new PriorityQueue<>();
        queue.add(11);
        queue.add(10);
        queue.add(22);
        queue.add(5);
        queue.add(12);
        queue.add(2);

        while (queue.isEmpty() == false)
            System.out.printf("%d ", queue.remove());

        System.out.println("\n");
    }
}

import java.util.*;

public class Treeset {
    public static void main(String[] args)
    {
        TreeSet<String> treeSet = new TreeSet<>();

        treeSet.add("Geeks");
        treeSet.add("For");
        treeSet.add("Geeks");
        treeSet.add("GeeksforGeeks");

        for (String temp : treeSet)
            System.out.printf(temp + " ");

        System.out.println("\n");
    }
}

import java.util.*;

public class linkedList {
    public static void main(String[] args)
    {
        List<String> list1 = new LinkedList<>();
        list1.add("Geeks");
        list1.add("For");
        list1.add("Geeks");
        list1.add("GFG");
        list1.add("GeeksforGeeks");

        List<String> list2 = new LinkedList<>();
        list2.add("Geeks");

        list1.removeAll(list2);

        for (String temp : list1)
            System.out.printf(temp + " ");

        System.out.println();
    }
}

import java.util.*;

public class hashSet {
    public static void main(String[] args)
    {
        HashSet<String> hashSet = new HashSet<>();
        hashSet.add("Geeks");
        hashSet.add("For");
        hashSet.add("Geeks");
        hashSet.add("GeeksforGeeks");

        System.out.println(hashSet);
    }
}

import java.util.*;

public class stack {
    public static void main(String[] args)
    {
        List<String> list = new LinkedList<>();
        list.add("Geeks");
        list.add("For");
        list.add("Geeks");
        list.add("GeeksforGeeks");
        Iterator<Integer> iter = list.iterator();

        while (iter.hasNext())
            System.out.printf(iter.next() + " ");

        System.out.println();
    }
}