Java by API/java.util/Queue

Queue: add(String e)

  
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
public class Main {
  public static void main(String[] args) {
    Queue<String> queue = new LinkedList<String>();
    queue.add("Hello");
    queue.add("World");
    List<String> list = new ArrayList<String>(queue);
    System.out.println(list);
  }
}

Queue: element()

 
import java.util.LinkedList;
import java.util.Queue;
public class Main {
  public static void main(String[] args) {
    Queue<String> queue = new LinkedList<String>();
    queue.offer("First");
    queue.offer("Second");
    queue.offer("Third");
    queue.offer("Fourth");
    System.out.println("Size: " + queue.size());
    System.out.println("Queue head using peek   : " + queue.peek());
    System.out.println("Queue head using element: " + queue.element());
    Object data;
    while ((data = queue.poll()) != null) {
      System.out.println(data);
    }
  }
}

Queue: peek()

 
import java.util.LinkedList;
import java.util.Queue;
public class Main {
  public static void main(String[] args) {
    Queue<String> queue = new LinkedList<String>();
    queue.offer("First");
    queue.offer("Second");
    queue.offer("Third");
    queue.offer("Fourth");
    System.out.println("Size: " + queue.size());
    System.out.println("Queue head using peek   : " + queue.peek());
    System.out.println("Queue head using element: " + queue.element());
    Object data;
    while ((data = queue.poll()) != null) {
      System.out.println(data);
    }
  }
}

Queue: poll()

 
import java.util.LinkedList;
import java.util.Queue;
public class Main {
  public static void main(String[] args) {
    Queue<String> queue = new LinkedList<String>();
    queue.offer("First");
    queue.offer("Second");
    queue.offer("Third");
    queue.offer("Fourth");
    System.out.println("Size: " + queue.size());
    System.out.println("Queue head using peek   : " + queue.peek());
    System.out.println("Queue head using element: " + queue.element());
    Object data;
    while ((data = queue.poll()) != null) {
      System.out.println(data);
    }
  }
}

Queue: size()

 
import java.util.LinkedList;
import java.util.Queue;
public class Main {
  public static void main(String[] args) {
    Queue<String> queue = new LinkedList<String>();
    queue.offer("First");
    queue.offer("Second");
    queue.offer("Third");
    queue.offer("Fourth");
    System.out.println("Size: " + queue.size());
    System.out.println("Queue head using peek   : " + queue.peek());
    System.out.println("Queue head using element: " + queue.element());
    Object data;
    while ((data = queue.poll()) != null) {
      System.out.println(data);
    }
  }
}