How to Convert an Array of Key-Value Pairs to a Dictionary in C#


How to Convert an Array of Key-Value Pairs to a Dictionary in C# ?

Answer

To convert an array of key-value pairs to a dictionary in C#, you can use the `ToDictionary` method from the `System.Linq` namespace. This allows you to create a dictionary from a collection of key-value pairs stored in an array.



✐ Examples

1 Converting an Array of Arrays to a Dictionary

We can convert an array of key-value pairs to a dictionary in C# using the `ToDictionary` method. This example demonstrates how to declare and initialize an array of key-value pairs, use the `ToDictionary` method to convert the array to a dictionary, and print the resulting dictionary.

For example,

  1. We start by including the necessary namespaces: using System.Collections.Generic; and using System.Linq;.
  2. We declare and initialize an array of key-value pairs named pairs. In this example, the pairs are represented as arrays with two elements: a key and a value.
  3. We use the `ToDictionary` method to convert the array to a dictionary.
  4. We print the resulting dictionary.

C# Program

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        // Declare and initialize an array of key-value pairs
        var pairs = new[]
        {
            new[] { 1, 10 },
            new[] { 2, 20 },
            new[] { 3, 30 }
        };

        // Convert the array to a dictionary using ToDictionary
        Dictionary<int, int> myDictionary = pairs.ToDictionary(pair => pair[0], pair => pair[1]);

        // Print the resulting dictionary
        Console.WriteLine("Dictionary from array of pairs:");
        foreach (var kvp in myDictionary)
        {
            Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);
        }
    }
}

Output

Dictionary from array of pairs:
Key: 1, Value: 10
Key: 2, Value: 20
Key: 3, Value: 30

2 Converting an Array of KeyValuePair to a Dictionary

We can convert an array of `KeyValuePair` to a dictionary in C# using the `ToDictionary` method. This example demonstrates how to declare and initialize an array of `KeyValuePair`, use the `ToDictionary` method to convert the array to a dictionary, and print the resulting dictionary.

For example,

  1. We start by including the necessary namespaces: using System.Collections.Generic; and using System.Linq;.
  2. We declare and initialize an array of `KeyValuePair` named pairs.
  3. We use the `ToDictionary` method to convert the array to a dictionary.
  4. We print the resulting dictionary.

C# Program

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        // Declare and initialize an array of KeyValuePair
        var pairs = new[]
        {
            new KeyValuePair<int, int>(1, 10),
            new KeyValuePair<int, int>(2, 20),
            new KeyValuePair<int, int>(3, 30)
        };

        // Convert the array to a dictionary using ToDictionary
        Dictionary<int, int> myDictionary = pairs.ToDictionary(pair => pair.Key, pair => pair.Value);

        // Print the resulting dictionary
        Console.WriteLine("Dictionary from array of KeyValuePair:");
        foreach (var kvp in myDictionary)
        {
            Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);
        }
    }
}

Output

Dictionary from array of KeyValuePair:
Key: 1, Value: 10
Key: 2, Value: 20
Key: 3, Value: 30

3 Converting an Array of Tuples to a Dictionary

We can convert an array of tuples to a dictionary in C# using the `ToDictionary` method. This example demonstrates how to declare and initialize an array of tuples, use the `ToDictionary` method to convert the array to a dictionary, and print the resulting dictionary.

For example,

  1. We start by including the necessary namespaces: using System.Collections.Generic; and using System.Linq;.
  2. We declare and initialize an array of tuples named pairs.
  3. We use the `ToDictionary` method to convert the array to a dictionary.
  4. We print the resulting dictionary.

C# Program

using System;
using System.Collections.Generic;
using System.Linq;

class Program
{
    static void Main()
    {
        // Declare and initialize an array of tuples
        var pairs = new[]
        {
            (1, 10),
            (2, 20),
            (3, 30)
        };

        // Convert the array to a dictionary using ToDictionary
        Dictionary<int, int> myDictionary = pairs.ToDictionary(pair => pair.Item1, pair => pair.Item2);

        // Print the resulting dictionary
        Console.WriteLine("Dictionary from array of tuples:");
        foreach (var kvp in myDictionary)
        {
            Console.WriteLine("Key: {0}, Value: {1}", kvp.Key, kvp.Value);
        }
    }
}

Output

Dictionary from array of tuples:
Key: 1, Value: 10
Key: 2, Value: 20
Key: 3, Value: 30

Summary

In this tutorial, we learned How to Convert an Array of Key-Value Pairs to a 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# ?