How to Get the Value Associated with a Key in a Dictionary in C#

How to Get the Value Associated with a Key in a Dictionary in C# ?

Answer

To get the value associated with a key in a dictionary in C#, you can use the indexer or the `TryGetValue` method of the `Dictionary` class from the `System.Collections.Generic` namespace.

✐ Examples

1 Getting the Value Associated with a Key Using the Indexer

We can get the value associated with a key in a dictionary in C# using the indexer. This example demonstrates how to retrieve the value for a specific key and print it.

For example,

We start by including the necessary namespace: using System.Collections.Generic;.
We declare and initialize a dictionary named myDictionary with integer keys and string values.
We use the indexer to get the value associated with a key.
We print the value associated with the key.

C# Program

using System;
using System.Collections.Generic;

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

        // Key to get the value for
        int keyToGet = 2;

        // Get the value associated with the key using the indexer
        string value = myDictionary[keyToGet];

        // Print the value associated with the key
        Console.WriteLine("The value associated with key {0} is '{1}'.", keyToGet, value);
    }
}

Output

The value associated with key 2 is 'Two'.

2 Getting the Value Associated with a Key Using the `TryGetValue` Method

We can get the value associated with a key in a dictionary in C# using the `TryGetValue` method. This example demonstrates how to safely retrieve the value for a specific key and print it if it exists.

For example,

We start by including the necessary namespace: using System.Collections.Generic;.
We declare and initialize a dictionary named myDictionary with integer keys and string values.
We use the `TryGetValue` method to get the value associated with a key.
We print the value associated with the key if it exists, or a message if it does not.

C# Program

using System;
using System.Collections.Generic;

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

        // Key to get the value for
        int keyToGet = 4;

        // Try to get the value associated with the key using the TryGetValue method
        if (myDictionary.TryGetValue(keyToGet, out string value))
        {
            // Print the value associated with the key
            Console.WriteLine("The value associated with key {0} is '{1}'.", keyToGet, value);
        }
        else
        {
            // Print a message if the key does not exist
            Console.WriteLine("The key {0} does not exist in the dictionary.", keyToGet);
        }
    }
}

Output

The key 4 does not exist in the dictionary.

Summary

In this tutorial, we learned How to Get the Value Associated with a Key in a Dictionary in C# language with well detailed examples.

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How to Get the Value Associated with a Key in a Dictionary in C#