How to create an OrderedDictionary in C#?

To create an OrderedDictionary in C#, the code is as follows −

Example

 Live Demo

using System;
using System.Collections;
using System.Collections.Specialized;
public class Demo {
   public static void Main() {
      OrderedDictionary dict = new OrderedDictionary();
      dict.Add("A", "Books");
      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.Remove("E");
      Console.WriteLine("Count of elements in OrderedDictionary (Updated)= " + dict.Count);
   }
}

Output

This will produce the following output −

OrderedDictionary elements...
A Books
B Electronics
C Smart Wearables
D Pet Supplies
E Clothing
F Footwear
Count of elements in OrderedDictionary = 6
Count of elements in OrderedDictionary (Updated)= 5

Example

Let us see another example −

 Live Demo

using System;
using System.Collections;
using System.Collections.Specialized;
public class Demo {
   public static void Main() {
      OrderedDictionary dict = new OrderedDictionary();
      dict.Add("1", "One");
      dict.Add("2", "Two");
      dict.Add("3", "Three");
      dict.Add("4", "Four");
      dict.Add("5", "Five");
      dict.Add("6", "Six");
      dict.Add("7", "Seven");
      dict.Add("8", "Eight");
      ICollection col = dict.Keys;
      String[] strKeys = new String[dict.Count];
      col.CopyTo(strKeys, 0);
      Console.WriteLine("Displaying the keys...");
      for (int i = 0; i < dict.Count; i++) {
         Console.WriteLine(strKeys[i]);
      }
   }
}

Output

This will produce the following output −

Displaying the keys...
1
2
3
4
5
6
7
8