Get the number of key/values pairs contained in OrderedDictionary in C#

The OrderedDictionary class in C# provides a Count property to get the number of key-value pairs it contains. This property returns an integer value representing the total number of elements in the collection.

OrderedDictionary is part of the System.Collections.Specialized namespace and maintains the insertion order of elements while allowing access by both key and index.

Syntax

Following is the syntax for accessing the Count property −

int count = orderedDictionary.Count;

Using Count Property with OrderedDictionary

Example

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

public class Demo {
   public static void Main(){
      OrderedDictionary dict = new OrderedDictionary();
      dict.Add("A", "Home Appliances");
      dict.Add("B", "Electronics");
      dict.Add("C", "Smart Wearables");
      dict.Add("D", "Pet Supplies");
      dict.Add("E", "Clothing");
      dict.Add("F", "Footwear");
      Console.WriteLine("OrderedDictionary elements...");
      foreach(DictionaryEntry d in dict){
         Console.WriteLine(d.Key + " " + d.Value);
      }
      Console.WriteLine("Count of elements in OrderedDictionary = " + dict.Count);
      dict.Clear();
      Console.WriteLine("Count of elements in OrderedDictionary (Updated)= " + dict.Count);
   }
}

The output of the above code is −

OrderedDictionary elements...
A Home Appliances
B Electronics
C Smart Wearables
D Pet Supplies
E Clothing
F Footwear
Count of elements in OrderedDictionary = 6
Count of elements in OrderedDictionary (Updated)= 0

Comparing Multiple OrderedDictionaries

Example

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

public class Demo {
   public static void Main(){
      OrderedDictionary dict1 = new OrderedDictionary();
      dict1.Add("A", "John");
      dict1.Add("B", "Andy");
      dict1.Add("C", "Jacob");
      dict1.Add("D", "Kevin");
      dict1.Add("E", "Gary");
      dict1.Add("F", "Nathan");
      dict1.Add("G", "Kevin");
      dict1.Add("H", "Ryan");
      Console.WriteLine("OrderedDictionary1 elements...");
      foreach(DictionaryEntry d in dict1){
         Console.WriteLine(d.Key + " " + d.Value);
      }
      Console.WriteLine("Count of key-value pairs in OrderedDictionary1 = " + dict1.Count);
      OrderedDictionary dict2 = new OrderedDictionary();
      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("\nOrderedDictionary2 elements...");
      foreach(DictionaryEntry d in dict2){
         Console.WriteLine(d.Key + " " + d.Value);
      }
      Console.WriteLine("Count of key-value pairs in OrderedDictionary2 = " + dict2.Count);
      Console.WriteLine("\nIs OrderedDictionary1 equal to OrderedDictionary2? = "+(dict1.Equals(dict2)));
      OrderedDictionary orderedDict = dict2.AsReadOnly();
      Console.WriteLine("Is OrderedDictionary read-only? = "+orderedDict.IsReadOnly);
   }
}

The output of the above code is −

OrderedDictionary1 elements...
A John
B Andy
C Jacob
D Kevin
E Gary
F Nathan
G Kevin
H Ryan
Count of key-value pairs in OrderedDictionary1 = 8

OrderedDictionary2 elements...
1 One
2 Two
3 Three
4 Four
5 Five
6 Six
Count of key-value pairs in OrderedDictionary2 = 6

Is OrderedDictionary1 equal to OrderedDictionary2? = False
Is OrderedDictionary read-only? = True

Dynamic Count Changes

Example

using System;
using System.Collections.Specialized;

public class Demo {
   public static void Main(){
      OrderedDictionary dict = new OrderedDictionary();
      Console.WriteLine("Initial count: " + dict.Count);
      
      dict.Add("Name", "Alice");
      Console.WriteLine("After adding 1 element: " + dict.Count);
      
      dict.Add("Age", "25");
      dict.Add("City", "New York");
      Console.WriteLine("After adding 3 elements total: " + dict.Count);
      
      dict.Remove("Age");
      Console.WriteLine("After removing 1 element: " + dict.Count);
      
      dict.RemoveAt(0);
      Console.WriteLine("After removing by index: " + dict.Count);
   }
}

The output of the above code is −

Initial count: 0
After adding 1 element: 1
After adding 3 elements total: 3
After removing 1 element: 2
After removing by index: 1

Conclusion

The Count property of OrderedDictionary provides a simple way to get the number of key-value pairs in the collection. This property updates automatically as elements are added or removed, making it useful for monitoring collection size and implementing conditional logic based on the number of elements.