Queue.Clear Method in C#

This method is used to remove the objects from the Queue. This method is an O(n) operation, where n is the total count of elements. And this method comes under System.Collections namespace.

Syntax:

public void Clear ();

Below given are some examples to understand the implementation in a better way:

Example 1:

// C# code to illustrate the
// Queue.Clear Method
using System;
using System.Collections;

class GFG {

    // Driver code
    public static void Main()
    {

        // Creating a Queue
        Queue q = new Queue();

        // Inserting the elements into the Queue
        q.Enqueue(1);
        q.Enqueue(2);
        q.Enqueue(2);
        q.Enqueue(4);

        // Displaying the count of elements
        // contained in the Queue before
        // removing all the elements
        Console.Write("Total number of elements "+
                           "in the Queue are : ");

        Console.WriteLine(q.Count);

        // Removing all elements from Queue
        q.Clear();

        // Displaying the count of elements
        // contained in the Queue after
        // removing all the elements
        Console.Write("Total number of elements"+
                         " in the Queue are : ");

        Console.WriteLine(q.Count);
    }
}

Output:

Total number of elements in the Queue are : 4
Total number of elements in the Queue are : 0

Example 2:

// C# code to illustrate the
// Queue.Clear Method
using System;
using System.Collections;

class GFG {

    // Driver code
    public static void Main()
    {

        // Creating a Queue
        Queue q = new Queue();

        // Inserting the elements into the Queue
        q.Enqueue("C");
        q.Enqueue("C++");
        q.Enqueue("Java");
        q.Enqueue("PHP");
        q.Enqueue("HTML");
        q.Enqueue("Python");

        // Displaying the count of elements
        // contained in the Queue before
        // removing all the elements
        Console.Write("Total number of elements "+
                           "in the Queue are : ");

        Console.WriteLine(q.Count);

        // Removing all elements from Queue
        q.Clear();

        // Displaying the count of elements
        // contained in the Queue after
        // removing all the elements
        Console.Write("Total number of elements "+
                           "in the Queue are : ");

        Console.WriteLine(q.Count);
    }
}

Output:

Total number of elements in the Queue are : 6
Total number of elements in the Queue are : 0

Reference:

• https://docs.microsoft.com/en-us/dotnet/api/system.collections.queue.clear?view=netframework-4.7.2