Queue represents a first-in, first out collection of object. It is used when you need a first-in, first-out access to items. When you add an item to the list, it is called enqueue, and when you remove an item, it is called deque.
The following table lists some of the commonly used methods of the Queue class −
| Sr.No | Method & Description |
|---|---|
| 1 | public virtual void Clear(); Removes all elements from the Queue. |
| 2 | public virtual bool Contains(object obj); Determines whether an element is in the Queue. |
| 3 | public virtual object Dequeue(); Removes and returns the object at the beginning of the Queue. |
| 4 | public virtual void Enqueue(object obj); Adds an object to the end of the Queue. |
| 5 | public virtual object[] ToArray(); Copies the Queue to a new array. |
Let us see an example of the Queue class −
Example
using System;
using System.Collections;
namespace Demo {
class Program {
static void Main(string[] args) {
Queue q = new Queue();
q.Enqueue('X');
q.Enqueue('Y');
q.Enqueue('Z');
Console.WriteLine("Current queue: ");
foreach (char c in q) Console.Write(c + " ");
Console.WriteLine();
q.Enqueue('A');
Console.WriteLine("Current queue: ");
foreach (char c in q) Console.Write(c + " ");
Console.WriteLine();
Console.ReadKey();
}
}
}Output
Current queue: X Y Z Current queue: X Y Z A