Queue

Description

Queue collection contains a group of elements based on FIFO (First-In-First-Out) principle.

Queue<T> referenceVariable = new Queue<T>();

Full Path: System.Collections.Generic.Queue
Elements are stored in a front-to-rear approach: Firstly-added item is at front, lastly-added item is at rear.
It is based on FIFO (First-In-First-Out) principle.
The Queue class is a generic class.
Elements cannot be accessed by index.

Example:

Queue<string> queue = new Queue<string>();

foreach (string item in queue) {
    Console.WriteLine(item); // Task 3, Task 5, ...
}

Features

Overview

Feature	Description
`Count`	Returns count of elements.
`Enqueue(T)`	Adds an element at the top of the queue.
`Dequeue()`	Removes and returns the element at the top of the queue.
`Peek()`	Returns the element at the top of the queue.
`Contains(T)`	Determines whether the specified element exists.
`ToArray()`	Converts the queue as an array.
`Clear()`	Removes all elements.

Info

All the shared features can be used for Queue

Enqueue

Is used to add elements to the end of a Queue<T> collection. The Enqueue method ensures that elements are added at the end of the queue.

Example:

queue.Enqueue("Task 3");
queue.Enqueue("Task 5");
queue.Enqueue("Task 1");
queue.Enqueue("Task 2");

Dequeue

Is used to remove and return the object at the beginning of the queue. When the method is called, it removes the item at the front of the queue and shifts all subsequent items forward.

Will remove the returned element.
If the queue is empty and you attempt to call Dequeue, an InvalidOperationException is thrown.

Example:

string dq = queue.Dequeue();
Console.WriteLine("Dequeue: " + dq);