How to create an Empty Dictionary in C#

How to create an Empty Dictionary in C# ?

Answer

To create an empty dictionary in C#, you can use the `Dictionary` class from the `System.Collections.Generic` namespace. You can specify the types for the keys and values in the dictionary.


✐ Examples

1 Creating an Empty Dictionary with Integer Keys and String Values

We can create an empty dictionary in C# where the keys are integers and the values are strings. This example demonstrates how to initialize an empty dictionary and add key-value pairs to it.

For example,

  1. We start by including the necessary namespace: using System.Collections.Generic;.
  2. We declare and initialize an empty dictionary named myDictionary with integer keys and string values.
  3. We add some key-value pairs to the dictionary using the Add method.
  4. We print the dictionary contents to verify the key-value pairs.

C# Program

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        // Declare and initialize an empty dictionary
        Dictionary<int, string> myDictionary = new Dictionary<int, string>();

        // Add key-value pairs to the dictionary
        myDictionary.Add(1, "One");
        myDictionary.Add(2, "Two");
        myDictionary.Add(3, "Three");

        // Print the dictionary contents
        Console.WriteLine("Dictionary contents:");
        foreach (KeyValuePair<int, string> kvp in myDictionary)
        {
            Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);
        }
    }
}

Output

Dictionary contents:
Key: 1, Value: One
Key: 2, Value: Two
Key: 3, Value: Three

2 Creating an Empty Dictionary with String Keys and Double Values

We can create an empty dictionary in C# where the keys are strings and the values are doubles. This example demonstrates how to initialize an empty dictionary and add key-value pairs to it.

For example,

  1. We start by including the necessary namespace: using System.Collections.Generic;.
  2. We declare and initialize an empty dictionary named myDictionary with string keys and double values.
  3. We add some key-value pairs to the dictionary using the Add method.
  4. We print the dictionary contents to verify the key-value pairs.

C# Program

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        // Declare and initialize an empty dictionary
        Dictionary<string, double> myDictionary = new Dictionary<string, double>();

        // Add key-value pairs to the dictionary
        myDictionary.Add("A", 1.1);
        myDictionary.Add("B", 2.2);
        myDictionary.Add("C", 3.3);

        // Print the dictionary contents
        Console.WriteLine("Dictionary contents:");
        foreach (KeyValuePair<string, double> kvp in myDictionary)
        {
            Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);
        }
    }
}

Output

Dictionary contents:
Key: A, Value: 1.1
Key: B, Value: 2.2
Key: C, Value: 3.3

Summary

In this tutorial, we learned How to create an Empty Dictionary in C# language with well detailed examples.


More C# Dictionaries Tutorials

  1. How to create an Empty Dictionary in C# ?
  2. How to create a Dictionary with Initial Key-Value Pairs in C# ?
  3. How to Print a Dictionary in C# ?
  4. How to Add a Key-Value Pair to a Dictionary in C# ?
  5. How to Set a Default Value for a Key in a Dictionary in C# ?
  6. How to Update the Value for a Key in a Dictionary in C# ?
  7. How to Check if a Dictionary is Empty in C# ?
  8. How to Check if a Key Exists in a Dictionary in C# ?
  9. How to Check if a Value Exists in a Dictionary in C# ?
  10. How to Get the Value Associated with a Key in a Dictionary in C# ?
  11. How to Remove a Key-Value Pair from a Dictionary in C# ?
  12. How to Remove Key-Value Pairs from a Dictionary Based on Values in C# ?
  13. How to Clear all Key-Value Pairs from a Dictionary in C# ?
  14. How to Iterate over Keys in a Dictionary in C# ?
  15. How to Iterate over Values in a Dictionary in C# ?
  16. How to Iterate over Entries (Key-Value Pairs) in a Dictionary in C# ?
  17. How to Get the Size (Number of Key-Value Pairs) of a Dictionary in C# ?
  18. How to Convert a Dictionary to an Array of Keys in C# ?
  19. How to Convert a Dictionary to an Array of Values in C# ?
  20. How to Convert a Dictionary to an Array of Key-Value Pairs in C# ?
  21. How to Merge Two Dictionaries in C# ?
  22. How to Clone a Dictionary in C# ?
  23. How to Check if Two Dictionaries are Equal in C# ?
  24. How to Sort a Dictionary by Keys in C# ?
  25. How to Sort a Dictionary by Values in C# ?
  26. How to Filter a Dictionary Based on Keys in C# ?
  27. How to Filter a Dictionary Based on Values in C# ?
  28. How to Reduce Values in a Dictionary to a Single Value in C# ?
  29. How to Convert an Array of Key-Value Pairs to a Dictionary in C# ?
  30. How to Convert a Dictionary to a JSON String in C# ?
  31. How to Convert a JSON String to a Dictionary in C# ?
  32. How to Swap Keys and Values in a Dictionary in C# ?
  33. How to Create a Dictionary of Dictionaries in C# ?
  34. How to Iterate Over a Dictionary of Dictionaries in C# ?