How to Convert a Dictionary to an Array of Keys in C#

How to Convert a Dictionary to an Array of Keys in C# ?

Answer

To convert a dictionary to an array of keys in C#, you can use the `Keys` property of the `Dictionary` class and the `ToArray` method from the `System.Linq` namespace. This allows you to create an array containing all the keys in the dictionary.

✐ Examples

1 Converting a Dictionary to an Array of Keys Using `Keys` and `ToArray`

We can convert a dictionary to an array of keys in C# using the `Keys` property and the `ToArray` method. This example demonstrates how to declare and initialize a dictionary, use the `Keys` property to get the keys, convert them to an array, and print the array of keys.

For example,

We start by including the necessary namespaces: using System.Collections.Generic; and using System.Linq;.
We declare and initialize a dictionary named myDictionary with integer keys and string values.
We use the `Keys` property to get the keys from the dictionary.
We use the `ToArray` method to convert the keys to an array.
We print the array of keys.

C# Program

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

class Program
{
    static void Main()
    {
        // Declare and initialize a dictionary
        Dictionary<int, string> myDictionary = new Dictionary<int, string>
        {
            {1, "One"},
            {2, "Two"},
            {3, "Three"}
        };

        // Convert the dictionary to an array of keys
        int[] keysArray = myDictionary.Keys.ToArray();

        // Print the array of keys
        Console.WriteLine("Array of keys:");
        foreach (int key in keysArray)
        {
            Console.WriteLine(key);
        }
    }
}

Output

Array of keys:
1
2
3

2 Converting an Empty Dictionary to an Array of Keys

We can convert an empty dictionary to an array of keys in C# using the `Keys` property and the `ToArray` method. This example demonstrates how to declare and initialize an empty dictionary, use the `Keys` property to get the keys, convert them to an array, and print the array of keys.

For example,

We start by including the necessary namespaces: using System.Collections.Generic; and using System.Linq;.
We declare and initialize an empty dictionary named myDictionary.
We use the `Keys` property to get the keys from the dictionary.
We use the `ToArray` method to convert the keys to an array.
We print the array of keys.

C# Program

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

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

        // Convert the dictionary to an array of keys
        int[] keysArray = myDictionary.Keys.ToArray();

        // Print the array of keys
        Console.WriteLine("Array of keys:");
        foreach (int key in keysArray)
        {
            Console.WriteLine(key);
        }
    }
}

Output

Array of keys:

Summary

In this tutorial, we learned How to Convert a Dictionary to an Array of Keys in C# language with well detailed examples.

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