C# | Removing all entries from HybridDictionary

HybridDictionary.Clear method is used to remove all entries from the HybridDictionary.

Syntax:

public void Clear ();

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

Example 1:

// C# code to removes all entries
// from the HybridDictionary.
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver code
    public static void Main()
    {

        // Creating a HybridDictionary named myDict
        HybridDictionary myDict = new HybridDictionary();

        // Adding key/value pairs in myDict
        myDict.Add("A", "Apple");
        myDict.Add("B", "Banana");
        myDict.Add("C", "Cat");
        myDict.Add("D", "Dog");
        myDict.Add("E", "Elephant");
        myDict.Add("F", "Fish");

        // Displaying the number of key/value
        // pairs in HybridDictionary myDict
        Console.WriteLine("Number of key/value pairs in myDict are : "
                                                      + myDict.Count);

        // Displaying the key/value pairs in myDict
        Console.WriteLine("The key/value pairs in myDict are : ");

        foreach(DictionaryEntry de in myDict)
        {
            Console.WriteLine(de.Key + " --> " + de.Value);
        }

        // Removing all entries from myDict
        myDict.Clear();

        // Displaying the number of key/value
        // pairs in HybridDictionary myDict
        Console.WriteLine("Number of key/value pairs in myDict are : "
                                                       + myDict.Count);

        // Displaying the key/value pairs in myDict
        Console.WriteLine("The key/value pairs in myDict are : ");

        foreach(DictionaryEntry de in myDict)
        {
            Console.WriteLine(de.Key + " --> " + de.Value);
        }
    }
}

Output:

Number of key/value pairs in myDict are : 6
The key/value pairs in myDict are : 
A --> Apple
B --> Banana
C --> Cat
D --> Dog
E --> Elephant
F --> Fish
Number of key/value pairs in myDict are : 0
The key/value pairs in myDict are : 

Example 2:

// C# code to removes all entries
// from the HybridDictionary.
using System;
using System.Collections;
using System.Collections.Specialized;

class GFG {

    // Driver code
    public static void Main()
    {

        // Creating a HybridDictionary named myDict
        HybridDictionary myDict = new HybridDictionary();

        // Adding key/value pairs in myDict
        myDict.Add("I", "first");
        myDict.Add("II", "second");
        myDict.Add("III", "third");
        myDict.Add("IV", "fourth");
        myDict.Add("V", "fifth");

        // Displaying the number of key/value
        // pairs in HybridDictionary myDict
        Console.WriteLine("Number of key/value pairs in myDict are : "
                                                      + myDict.Count);

        // Displaying the key/value pairs in myDict
        Console.WriteLine("The key/value pairs in myDict are : ");

        foreach(DictionaryEntry de in myDict)
        {
            Console.WriteLine(de.Key + " --> " + de.Value);
        }

        // Removing all entries from myDict
        myDict.Clear();

        // Displaying the number of key/value
        // pairs in HybridDictionary myDict
        Console.WriteLine("Number of key/value pairs in myDict are : "
                                                       + myDict.Count);

        // Displaying the key/value pairs in myDict
        Console.WriteLine("The key/value pairs in myDict are : ");

        foreach(DictionaryEntry de in myDict)
        {
            Console.WriteLine(de.Key + " --> " + de.Value);
        }
    }
}

Output:

Number of key/value pairs in myDict are : 5
The key/value pairs in myDict are : 
I --> first
II --> second
III --> third
IV --> fourth
V --> fifth
Number of key/value pairs in myDict are : 0
The key/value pairs in myDict are :

Note:

• Count is set to zero, and references to other objects from elements of the collection are also released.
• If the collection is already stored in a Hashtable, the collection remains in the Hashtable.
• This method is an O(n) operation, where n is Count.

Reference:

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