Queue.Dequeue Method in C#

The Queue.Dequeue() method in C# is used to remove and return the object at the beginning of the Queue.

Syntax

The syntax is as follows −

public virtual object Dequeue ();

Example

Let us now see an example −

 Live Demo

using System;
using System.Collections.Generic;
public class Demo {
   public static void Main() {
      Queue<string> queue = new Queue<string>();
      queue.Enqueue("A");
      queue.Enqueue("B");
      queue.Enqueue("C");
      queue.Enqueue("D");
      queue.Enqueue("E");
      queue.Enqueue("F");
      queue.Enqueue("G");
      Console.WriteLine("Count of elements = "+queue.Count);
      Console.WriteLine("Element at the beginning of queue = " + queue.Peek());
      queue.Dequeue();
      queue.Dequeue();
      queue.Dequeue();
      Console.WriteLine("Count of elements = "+queue.Count);
   }
}

Output

This will produce the following output −

Count of elements = 7
Element at the beginning of queue = A
Count of elements = 4

Example

Let us now see another example −

 Live Demo

using System;
using System.Collections.Generic;
public class Demo {
   public static void Main() {
      Queue<string> queue = new Queue<string>();
      queue.Enqueue("Gary");
      queue.Enqueue("Jack");
      queue.Enqueue("Ryan");
      queue.Enqueue("Kevin");
      queue.Enqueue("Mark");
      queue.Enqueue("Jack");
      queue.Enqueue("Ryan");
      queue.Enqueue("Kevin");
      Console.Write("Count of elements = ");
      Console.WriteLine(queue.Count);
      Console.WriteLine("Queue...");
      foreach(string i in queue) {
         Console.WriteLine(i);
      }
      queue.Dequeue();
      queue.Dequeue();
      Console.WriteLine("Queue...UPDATED");
      foreach(string i in queue) {
         Console.WriteLine(i);
      }
      Console.Write("Count of elements (updated) = "+queue.Count);
      queue.Clear();
      Console.Write("
Count of elements (updated AGAIN) = ");
      Console.WriteLine(queue.Count);
   }
}

Output

This will produce the following output −

Count of elements = 8
Queue...
Gary
Jack
Ryan
Kevin
Mark
Jack
Ryan
Kevin
Queue...UPDATED
Ryan
Kevin
Mark
Jack
Ryan
Kevin
Count of elements (updated) = 6
Count of elements (updated AGAIN) = 0