Count the number of key/value pairs in HybridDictionary in C#

A HybridDictionary in C# is a collection that automatically switches between a ListDictionary for small collections and a Hashtable for larger collections. To count the number of key/value pairs in a HybridDictionary, we use the Count property.

The HybridDictionary optimizes performance by using different internal storage mechanisms based on the number of elements. For collections with 10 or fewer items, it uses a ListDictionary, and for larger collections, it switches to a Hashtable.

Syntax

Following is the syntax for getting the count of key/value pairs in a HybridDictionary −

HybridDictionary dictionary = new HybridDictionary();
int count = dictionary.Count;

Using Count Property

The Count property returns the total number of key/value pairs currently stored in the HybridDictionary −

Example

using System;
using System.Collections;
using System.Collections.Specialized;

public class Demo {
   public static void Main(){
      HybridDictionary dict1 = new HybridDictionary();
      dict1.Add("A", "SUV");
      dict1.Add("B", "MUV");
      dict1.Add("C", "AUV");
      Console.WriteLine("HybridDictionary1 elements...");
      foreach(DictionaryEntry d in dict1){
         Console.WriteLine(d.Key + " " + d.Value);
      }
      Console.WriteLine("Count of Key/value pairs in Dictionary1 = "+dict1.Count);
      HybridDictionary dict2 = new HybridDictionary();
      dict2.Add("1", "One");
      dict2.Add("2", "Two");
      dict2.Add("3", "Three");
      dict2.Add("4", "Four");
      dict2.Add("5", "Five");
      dict2.Add("6", "Six");
      Console.WriteLine("\nHybridDictionary2 elements...");
      foreach(DictionaryEntry d in dict2){
         Console.WriteLine(d.Key + " " + d.Value);
      }
      Console.WriteLine("Count of Key/value pairs in Dictionary2 = "+dict2.Count);
      dict2.Clear();
      Console.WriteLine("Count of Key/value pairs in Dictionary2 (Updated) = "+dict2.Count);
   }
}

The output of the above code is −

HybridDictionary1 elements...
A SUV
B MUV
C AUV
Count of Key/value pairs in Dictionary1 = 3

HybridDictionary2 elements...
1 One
2 Two
3 Three
4 Four
5 Five
6 Six
Count of Key/value pairs in Dictionary2 = 6
Count of Key/value pairs in Dictionary2 (Updated) = 0

Count Property with Dynamic Operations

Example

using System;
using System.Collections;
using System.Collections.Specialized;

public class Demo {
   public static void Main(){
      HybridDictionary dict = new HybridDictionary();
      dict.Add("A", "SUV");
      dict.Add("B", "MUV");
      dict.Add("C", "AUV");
      Console.WriteLine("HybridDictionary elements...");
      foreach(DictionaryEntry d in dict){
         Console.WriteLine(d.Key + " " + d.Value);
      }
      Console.WriteLine("Count of Key/value pairs in Dictionary = "+dict.Count);
      dict.Add("D", "Utility Vehicle");
      dict.Add("E", "Convertible");
      Console.WriteLine("Count of Key/value pairs in Dictionary (Updated) = "+dict.Count);
   }
}

The output of the above code is −

HybridDictionary elements...
A SUV
B MUV
C AUV
Count of Key/value pairs in Dictionary = 3
Count of Key/value pairs in Dictionary (Updated) = 5

Key Features

• The Count property returns an int representing the total number of key/value pairs.

• The count is automatically updated when items are added or removed from the HybridDictionary.

• Using Clear() method sets the count to zero by removing all elements.

• The Count property has O(1) time complexity, making it efficient for frequent count operations.

Conclusion

The Count property of HybridDictionary provides an efficient way to determine the number of key/value pairs in the collection. This property automatically updates as items are added or removed, making it reliable for tracking collection size in real-time applications.