ListDictionary Class in C#

CsharpServer Side ProgrammingProgramming

The ListDictionary class implements IDictionary using a singly linked list. It is recommended for collections that typically include fewer than 10 items.

Following are the properties of ListDictionary class −

Sr.NoProperty & Description
1Count
Gets the number of key/value pairs contained in the ListDictionary.
2IsFixedSize
Gets a value indicating whether the ListDictionary has a fixed size.
3IsReadOnly
Gets a value indicating whether the ListDictionary is readonly.
4IsSynchronized
Gets a value indicating whether the ListDictionary is synchronized (thread safe).
5Item[Object]
Gets or sets the value associated with the specified.
6Keys
Gets an ICollection containing the keys in the ListDictionary.
7SyncRoot
Gets an object that can be used to synchronize access to the ListDictionary.
8Values
Gets an ICollection containing the values in the ListDictionary.

Following are some of the methods of the ListDictionary class −

Sr.NoMethods & Description
1Add(Object, Object)
Adds an entry with the specified key and value into the ListDictionary.
2Clear()
Removes all entries from the ListDictionary.
3Contains(Object)
Determines whether the ListDictionary contains a specific key.
4CopyTo(Array, Int32)
Copies the ListDictionary entries to a onedimensional Array instance at the specified index.
5Equals(Object)
Determines whether the specified object is equal to the current object. (Inherited from Object)
6GetEnumerator()
Returns an IDictionaryEnumerator that iterates through the ListDictionary.
7GetHashCode()
Serves as the default hash function. (Inherited from Object)
8GetType()
Gets the Type of the current instance. (Inherited from Object)

Example

Let us now see some examples −

To check if ListDictionary is read-only, the code is as follows −

 Live Demo

using System;
using System.Collections;
using System.Collections.Specialized;
public class Demo {
   public static void Main() {
      ListDictionary dict1 = new ListDictionary();
      dict1.Add("A", "Books");
      dict1.Add("B", "Electronics");
      dict1.Add("C", "Smart Wearables");
      dict1.Add("D", "Pet Supplies");
      dict1.Add("E", "Clothing");
      dict1.Add("F", "Footwear");
      Console.WriteLine("ListDictionary1 elements...");
      foreach(DictionaryEntry d in dict1) {
         Console.WriteLine(d.Key + " " + d.Value);
      }
      Console.WriteLine("Is the ListDictionary1 having fixed size? = "+dict1.IsFixedSize);
      Console.WriteLine("If ListDictionary1 read-only? = "+dict1.IsReadOnly);
      Console.WriteLine("Is ListDictionary1 synchronized = "+dict1.IsSynchronized);
      Console.WriteLine("The ListDictionary1 has the key M? = "+dict1.Contains("M"));
      ListDictionary dict2 = new ListDictionary();
      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("\nListDictionary2 key-value pairs...");
      IDictionaryEnumerator demoEnum = dict2.GetEnumerator();
      while (demoEnum.MoveNext())
      Console.WriteLine("Key = " + demoEnum.Key + ", Value = "+ demoEnum.Value);
      Console.WriteLine("Is the ListDictionary2 having fixed size? = "+dict2.IsFixedSize);
      Console.WriteLine("If ListDictionary2 read-only? = "+dict2.IsReadOnly);
      Console.WriteLine("Is ListDictionary2 synchronized = "+dict2.IsSynchronized);
      Console.WriteLine("The ListDictionary2 has the key 5? = "+dict2.Contains("5"));
   }
}

Output

This will produce the following output −

ListDictionary1 elements...
A Books
B Electronics
C Smart Wearables
D Pet Supplies
E Clothing
F Footwear
Is the ListDictionary1 having fixed size? = False
If ListDictionary1 read-only? = False
Is ListDictionary1 synchronized = False
The ListDictionary1 has the key M? = False
ListDictionary2 key-value pairs...
Key = 1, Value = One
Key = 2, Value = Two
Key = 3, Value = Three
Key = 4, Value = Four
Key = 5, Value = Five
Key = 6, Value = Six
Is the ListDictionary2 having fixed size? = False
If ListDictionary2 read-only? = False
Is ListDictionary2 synchronized = False
The ListDictionary2 has the key 5? = True

To check if two ListDictionary objects are equal, the code is as follows −

Example

 Live Demo

using System;
using System.Collections;
using System.Collections.Specialized;
public class Demo {
   public static void Main() {
      ListDictionary dict1 = new ListDictionary();
      dict1.Add("A", "Books");
      dict1.Add("B", "Electronics");
      dict1.Add("C", "Smart Wearables");
      dict1.Add("D", "Pet Supplies");
      dict1.Add("E", "Clothing");
      dict1.Add("F", "Footwear");
      Console.WriteLine("ListDictionary1 elements...");
      foreach(DictionaryEntry d in dict1) {
         Console.WriteLine(d.Key + " " + d.Value);
      }
      ListDictionary dict2 = new ListDictionary();
      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("\nListDictionary2 elements...");
      foreach(DictionaryEntry d in dict2) {
         Console.WriteLine(d.Key + " " + d.Value);
      }
      ListDictionary dict3 = new ListDictionary();
      dict3 = dict2;
      Console.WriteLine("\nIs ListDictionary3 equal to ListDictionary2? = "+(dict3.Equals(dict2)));
   }
}

Output

This will produce the following output −

ListDictionary1 elements...
A Books
B Electronics
C Smart Wearables
D Pet Supplies
E Clothing
F Footwear
ListDictionary2 elements...
1 One
2 Two
3 Three
4 Four
5 Five
6 Six
Is ListDictionary3 equal to ListDictionary2? = True
raja
Published on 16-Dec-2019 08:08:06
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