C# | SortedDictionary.Item[] Property
Last Updated :
11 Jul, 2025
This property is used to get or set the value associated with the specified key.
Syntax:
public TValue this[TKey key] { get; set; }
Here,
key is the Key of the value to get or set.
Property Value: The value associated with the specified
key. If the specified
key is not found, a get operation throws a
KeyNotFoundException, and a set operation creates a new element with the specified key.
Exceptions:
- ArgumentNullException: If the key is null.
- KeyNotFoundException: If the property is retrieved and key does not exist in the collection.
Example:
csharp
// C# code to get or set the value
// associated with the specified key
using System;
using System.Collections;
using System.Collections.Generic;
class GFG {
// Driver code
public static void Main()
{
// Creating a SortedDictionary named myDict
SortedDictionary<string, string> myDict =
new SortedDictionary<string, string>();
// Adding key/value pairs in myDict
myDict.Add("Australia", "Canberra");
myDict.Add("Belgium", "Brussels");
myDict.Add("Netherlands", "Amsterdam");
myDict.Add("China", "Beijing");
myDict.Add("Russia", "Moscow");
myDict.Add("India", "New Delhi");
// Displaying the key/value pairs in myDict
foreach(KeyValuePair<string, string> k in myDict)
{
Console.WriteLine("Key = {0}, Value = {1}",
k.Key, k.Value);
}
// Displaying the value associated
// with key "Russia"
Console.Write("\nValue associated with Russia: ");
Console.Write(myDict["Russia"]);
// Setting the value associated with key "Russia"
myDict["Russia"] = "Saint Petersburg";
// Displaying the value associated
// with key "Russia"
Console.Write("\n\nValue associated with"+
" Russia After Setting: ");
Console.Write(myDict["Russia"]);
// Displaying the value associated
// with key "India"
Console.Write("\n\nValue associated with India: ");
Console.Write(myDict["India"]);
// Setting the value associated with key "India"
myDict["India"] = "Mumbai";
// Displaying the value associated
// with key "India"
Console.Write("\n\nValue associated "+
"with India After Setting: ");
Console.Write(myDict["India"]);
Console.WriteLine("\n");
// Displaying the key/value pairs in myDict
foreach(KeyValuePair<string, string> k1 in myDict)
{
Console.WriteLine("Key = {0}, Value = {1}",
k1.Key, k1.Value);
}
}
}
Output:
Key = Australia, Value = Canberra
Key = Belgium, Value = Brussels
Key = China, Value = Beijing
Key = India, Value = New Delhi
Key = Netherlands, Value = Amsterdam
Key = Russia, Value = Moscow
Value associated with Russia: Moscow
Value associated with Russia After Setting: Saint Petersburg
Value associated with India: New Delhi
Value associated with India After Setting: Mumbai
Key = Australia, Value = Canberra
Key = Belgium, Value = Brussels
Key = China, Value = Beijing
Key = India, Value = Mumbai
Key = Netherlands, Value = Amsterdam
Key = Russia, Value = Saint Petersburg
Reference:
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