How to use the Queue in C#, using Generics type objects

Suppose we have a simple class Employees:

Code:

protected class Employees : IComparable
{
	private string name = String.Empty;
	private int age = 0;
	private double salary = 0.0d;

	public string Name 
	{ 
		get { return name; }

		set { name= value; }
	}

	public int Age
	{
		get { return age; }

		set { age = value; }
	}

	public double Salary
	{
		get { return salary; }

		set { salary = value; }
	}

	/// <summary>
	/// The constructor of the class Employees
	/// </summary>
	/// <param name="n"></param>
	/// <param name="a"></param>
	/// <param name="s"></param>
	public Employees(string n, int a, double s)
	{
		name = n;
		age = a;
		salary = s;
	}

	/// <summary>
	/// Override the ToString() method
	/// </summary>
	/// <returns></returns>
	override public string ToString()
	{
		return String.Format("{0:s}, {1:G} - Salary: {2:c}",name, age, salary);
	}

	/// <summary>
	/// Override the CompareTo method,
	/// compare name fields
	/// </summary>
	/// <param name="obj"></param>
	/// <returns></returns>
	public int CompareTo(object obj)
	{
		Employees otherEmployees = obj as Employees;
		if (otherEmployees != null)
			return this.name.CompareTo(otherEmployees.name);
		else
			throw new ArgumentException("Object is not a Employees");
	}
}

Example of how to use the functions to manage the Queue:

Code:

// Create an instance of a Queue of Employees type
Queue<Employees> employees = new Queue<Employees>();

// Insert some objects of type "Employees" in the Queue
employees.Enqueue(new Employees("Yasmine", 32, 1800.00d));
employees.Enqueue(new Employees("Gabrielle", 38, 2300.00d));
employees.Enqueue(new Employees("Lynette", 35, 2200.00d));
employees.Enqueue(new Employees("Asia", 33, 1900.00d));

// Print the contents of the Queue
Response.Write("<h2>Content of Queue:</h2>");
foreach(Employees emp in employees)
{
	Response.Write(emp.ToString() + "<br />");
}

// Print the number of elements in the Queue
Response.Write("<code>employees.Count</code>: " + employees.Count + "<br />");


Employees employ = null;

// Extract some objects from the Queue
employ = employees.Dequeue();
Response.Write("<code>employees.Dequeue()</code>: " + employ.ToString() + "<br />");
Response.Write("<code>employees.Count</code>: " + employees.Count + "<br />");
employ = employees.Dequeue();
Response.Write("<code>employees.Dequeue()</code>: " + employ.ToString() + "<br />");
Response.Write("<code>employees.Count</code>: " + employees.Count + "<br />");

// Insert some objects of type "Employees" in the Queue
employees.Enqueue(new Employees("Daisy", 36, 2000.00d));
employees.Enqueue(new Employees("Lorelayne", 39, 2100.00d));
employees.Enqueue(new Employees("Jenny", 36, 2300.00d));
employees.Enqueue(new Employees("Lisa", 34, 2600.00d));
employees.Enqueue(new Employees("Ylenia", 37, 1700.00d));

// Print the contents of the Queue
Response.Write("<h2>Content of Queue:</h2>");
foreach (Employees emp in employees)
{
	Response.Write(emp.ToString() + "<br />");
}

// Extract some objects from the Queue
employ = employees.Dequeue();
Response.Write("<code>employees.Dequeue()</code>: " + employ.ToString() + "<br />");
Response.Write("<code>employees.Count</code>: " + employees.Count + "<br />");
employ = employees.Dequeue();
Response.Write("<code>employees.Dequeue()</code>: " + employ.ToString() + "<br />");
Response.Write("<code>employees.Count</code>: " + employees.Count + "<br />");
employ = employees.Peek();
Response.Write("<code>employees.Peek()</code>: " + employ.ToString() + "<br />");
Response.Write("<code>employees.Count</code>: " + employees.Count + "<br />");

// Print the contents of the Queue
Response.Write("<h2>Content of Queue:</h2>");
foreach (Employees emp in employees)
{
	Response.Write(emp.ToString() + "<br />");
}
Response.Write("<code>employees.Count</code>: " + employees.Count + "<br />");

// Copy the contents of the Queue in an array
Employees[] employeesArray= employees.ToArray();

// Print only the name and age of the employees within the array
Response.Write("<h2>Content of Employees[]:</h2>");
foreach (Employees emp in employeesArray)
{
	Response.Write(String.Format("{0} ({1})<br />", emp.Name, emp.Age ));
}

Description of functions used:

employees.Enqueue(new Employees("Daisy", 36, 2000.00d)); // Adds an object to the end of the Queue

employ = employees.Dequeue(); // Removes and returns the object at the beginning of the Queue

employ = employees.Peek(); // Returns the object at the beginning of the Queue without removing it

Employees[] employeesArray= employees.ToArray(); // Copy the contents of the Queue in an array

Here is the result for the sample:

Content of Queue:

Yasmine, 32 - Salary: $1,800.00
Gabrielle, 38 - Salary: $2,300.00
Lynette, 35 - Salary: $2,200.00
Asia, 33 - Salary: $1,900.00
employees.Count: 4
employees.Dequeue(): Yasmine, 32 - Salary: $1,800.00
employees.Count: 3
employees.Dequeue(): Gabrielle, 38 - Salary: $2,300.00
employees.Count: 2

Content of Queue:

Lynette, 35 - Salary: $2,200.00
Asia, 33 - Salary: $1,900.00
Daisy, 36 - Salary: $2,000.00
Lorelayne, 39 - Salary: $2,100.00
Jenny, 36 - Salary: $2,300.00
Lisa, 34 - Salary: $2,600.00
Ylenia, 37 - Salary: $1,700.00
employees.Dequeue(): Lynette, 35 - Salary: $2,200.00
employees.Count: 6
employees.Dequeue(): Asia, 33 - Salary: $1,900.00
employees.Count: 5
employees.Peek(): Daisy, 36 - Salary: $2,000.00
employees.Count: 5

Content of Queue:

Daisy, 36 - Salary: $2,000.00
Lorelayne, 39 - Salary: $2,100.00
Jenny, 36 - Salary: $2,300.00
Lisa, 34 - Salary: $2,600.00
Ylenia, 37 - Salary: $1,700.00
employees.Count: 5

Content of Employees[]:

Daisy (36)
Lorelayne (39)
Jenny (36)
Lisa (34)
Ylenia (37)