C# Sorteddictionary

The SortedDictionary is related to System.Collections.Generic namespace. SortedDictionary contains on key-value pairs. Where the keys are automatically sorted in ascending order.

Features with sorteddictionary in C#:

• Creating a SortedDictionary:

  You must use System.Collections.Generic before use of SortedDictionary. You can use the following syntax to create the SortedDictionary.

  Example

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  using System;

  using System.Collections.Generic;

  SortedDictionary<string,int> dictfruitprices = new SortedDictionary<string,int>();

  SortedDictionary<string,string> dictfruitnames = new SortedDictionary<string,string>();

• Adding Key-Value Pairs:

  You can add key-value pairs to a SortedDictionary using the Add method or by using the indexer:

  Example

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  // inserting fruit items in key-value pair

  dictfruitprices.Add("Apple",16);

  dictfruitprices.Add("Orange",12);

  dictfruitprices.Add("Cherry",18);

  dictfruitprices["Papaya"] = 20;

  dictfruitprices["Grape"] = 6;

  // inserting fruit items in key-value pair

  dictfruitnames.Add("Apple","Red");

  dictfruitnames.Add("Mango","Yellow");

  dictfruitnames.Add("Cherry","Red");

  dictfruitnames.Add("Orange","Dark Orange");

  dictfruitnames["Grape"] = "Violet";

  dictfruitnames.["Kiwi"] = "Spring Green";

• Accessing Values:

  You can retrieve values from the SortedDictionary using their associated keys:

  Example

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  // Returns 20

  int fruitprice = dictfruitprices["Papaya"];

  // Returns Violet

  int fruitcolor = dictfruitnames["Grape"];

• Checking for Key Existence:

  You can check if a key exists in the SortedDictionary using the ContainsKey method, similar to the Dictionary:

  Example

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  // Returns true

  bool containsAlice = dictfruitprices.ContainsKey("Papaya");

  // Returns true

  bool containsAlice = dictfruitnames.ContainsKey("Grape");

• Iterating through a Dictionary:

  You can use a foreach loop to iterate through the key-value pairs in a SortedDictionary. The items are automatically sorted by key:

  Example

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  foreach (var item1 in dictfruitprices)

  {

  Console.WriteLine($"{item1.Key}: {item1.Value}");

  }

  foreach (var item2 in dictfruitnames)

  {

  Console.WriteLine($"{item2.Key}: {item2.Value}");

  }

• Removing Key-Value Pairs:

  You can remove key-value pairs from the SortedDictionary using the Remove method:

  Example

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  dictfruitprices.Remove("Orange");

  dictfruitnames.Remove("Orange");

• Count of Key-Value Pairs:

  You can find the number of key-value pairs in the SortedDictionary using the Count property:

  Example

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  int count1 = dictfruitprices.Count;

  int count2 = dictfruitnames.Count;

• Sorted Dictionary in C# with Example

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  using System;

  using System.Collections.Generic;

  public class CSharpProgram

  {

  public static void Main(string[] arge)

  {

  SortedDictionary<string,int> dictfruitprices = new SortedDictionary<string,int>();

  SortedDictionary<string,string> dictfruitnames = new SortedDictionary<string,string>();

  // inserting fruit items in key-value pair

  dictfruitprices.Add("Apple",16);

  dictfruitprices.Add("Orange",12);

  dictfruitprices.Add("Cherry",18);

  dictfruitprices["Papaya"] = 20;

  dictfruitprices["Grape"] = 6;

  // inserting fruit items in key-value pair

  dictfruitnames.Add("Apple","Red");

  dictfruitnames.Add("Mango","Yellow");

  dictfruitnames.Add("Cherry","Red");

  dictfruitnames.Add("Orange","Dark Orange");

  dictfruitnames["Grape"] = "Violet";

  dictfruitnames["Kiwi"] = "Spring Green";

  foreach (var fruitprice1 in dictfruitprices)

  {

  Console.WriteLine($"{fruitprice1.Key}: {fruitprice1.Value}");

  }

  foreach (var fruitcolor1 in dictfruitnames)

  {

  Console.WriteLine($"{fruitcolor1.Key}: {fruitcolor1.Value}");

  }

  dictfruitprices.Remove("Orange");

  dictfruitnames.Remove("Orange");

  foreach (var fruitprice2 in dictfruitprices)

  {

  Console.WriteLine($"{fruitprice2.Key}: {fruitprice2.Value}");

  }

  foreach (var fruitcolor2 in dictfruitnames)

  {

  Console.WriteLine($"{fruitcolor2.Key}: {fruitcolor2.Value}");

  }

  }

  }

  
  
  

  Output

  Orange: 12

  Papaya: 20

  Apple: Red

  Cherry: Red

  Grape: Violet

  Kiwi: Spring Green

  Mango: Yellow

  Orange: Dark Orange

  Apple: 16

  Cherry: 18

  Grape: 6

  Papaya: 20

  Apple: Red

  Cherry: Red

  Grape: Violet

  Kiwi: Spring Green

  Mango: Yellow

Summary

SortedDictionary is particularly useful when you need both key-based lookup and an ordered collection of keys. It can be used for various scenarios where you need to maintain key-value pairs sorted by keys, such as dictionaries with configuration settings or maintaining data in sorted order.