Queue class in C#

• Queue class is a circular array that stores elements in First In First Out(FIFO) manner, i.e. Element that gets added first into the queue will get removed first from the queue.
• Element gets added from one end and removed from other end.
• Use queue when you want to access element in the same order that it is stored in the collection. 
• Use Queue if you want to discard the element as soon as you retrieve it.

See below example of using queue with its main functions.

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Code

using System;
using System.Collections;
 
namespace Queue_Collection_Class
{
    class Program
    {
        static void Main(string[] args)
        {
            Queue qEmp = new Queue();
 
            Employee emp1 = new Employee() { empId = 111, empName = "Sam" };
            Employee emp2 = new Employee() { empId = 112, empName = "Jane" };
            Employee emp3 = new Employee() { empId = 113, empName = "Sachin" };
            Employee emp4 = new Employee() { empId = 114, empName = "Jack" };
 
            qEmp.Enqueue(emp1);
            qEmp.Enqueue(emp2);
            qEmp.Enqueue(emp3);
            qEmp.Enqueue(emp4);
 
            Console.WriteLine("Retrieving elements from Queue\n");
 
            while (qEmp.Count>0)
            {
                Console.WriteLine("Employee Id: {0} information", ((Employee)qEmp.Peek()).empId);
                Employee emp = (Employee)qEmp.Dequeue();
                Console.WriteLine("Emplopyee Id : {0} \t Employee Name : {1}", emp.empId,emp.empName);
                Console.WriteLine("Elements in Queue are:{0}\n",qEmp.Count);
            }
 
            Console.ReadLine();
        }
    }
 
    public class Employee
    {
        public int empId { get; set; }
        public string empName { get; set; }
    }
}

In the above code sample, We have created a class called Employee with 2 Properties empId, empName.
We have created a Queue class object qEmp and storing few Employee objects in it. Below are the main functions of Queue that we used in our above code.

Enqueue : Add the element at the end of of Queue.
Dequeue : Retrieve and remove the first element from the Queue.
Peek : Peek function retrieves first element from the Queue but it does not remove it.

Below is the output of above program