SortedList <TKey, TValue> in C#

DevSniper
Published : 03 March 2024

120 Views

Sorting C#List Language-Concepts C# Collection

Namespace :- System.Collections.Generic

Assembly :- System.Collections.dll

Signature :-

public class SortedList<TKey,TValue> : 
    System.Collections.Generic.ICollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>,
    System.Collections.Generic.IDictionary<TKey,TValue>, 
    System.Collections.Generic.IEnumerable<System.Collections.Generic.KeyValuePair<TKey,TValue>>, 
    System.Collections.Generic.IReadOnlyCollection<System.Collections.Generic.KeyValuePair<TKey,TValue>>, 
    System.Collections.Generic.IReadOnlyDictionary<TKey,TValue>,
    System.Collections.IDictionary

It is used to store key/value pairs in the sorted order of key
By default , It will store data in ascending of key
it does not store duplicate key. key must be unique.
Value can be null in the case of reference type
It allowed only the same type of key/value pair data
Generic class SortedList<TKey,TValue> is an array of key/value pairs. With retrieval/get complexity O(log n)
SortedList<TKey,TValue> uses less memory than SortedDictionary<TKey,TValue>.
SortedDictionary<TKey,TValue> and SortedList<TKey,TValue> both has o( log n) time complexity for getting/retrieval of data
SortedList<TKey,TValue> is faster than SortedDictionary<TKey,TValue> if list is created all at once from sorted data.
For unsorted data , SortedDictionary<TKey,TValue> performs faster insertion and removal operations in O(log n) compared to SortedList<TKey,TValue> which performs these operations in O(n).
The capacity of SortedList<TKey,TValue> is a number of element that SortedList<TKey,TValue> can hold. Whenever we add a new element in the SortedList<TKey,TValue>the capacity is automatically increased as required by reallocating the internal array.
Capacity of the SortedList<TKey,TValue> can be decreased by calling TrimExcess or by setting the Capacity property explicitly.whenever we decrease the capacity, This process will reallocates memory and copies all the elements in the SortedList<TKey,TValue>.

SortedList<TKey, TValue> Constructors

public SortedList ();
public SortedList (System.Collections.Generic.IComparer<TKey>? comparer);
public SortedList (System.Collections.Generic.IDictionary<TKey,TValue> dictionary);
public SortedList (System.Collections.Generic.IDictionary<TKey,TValue> dictionary, System.Collections.Generic.IComparer<TKey>? comparer);
public SortedList (int capacity);
public SortedList (int capacity, System.Collections.Generic.IComparer<TKey>? comparer);

SortedList <TKey, TValue> Properties

Capacity :- public int Capacity { get; set; }
Gets the number of elements that SortedList<TKey,TValue> can store. getting the value of capacity is O(1) operation and setting the capacity property is O(n) operation.
Comparer :- public System.Collections.Generic.IComparer<TKey> Comparer { get; }
Gets the IComparer<TKey> that is used to sort/order element of the SortedList<TKey,TValue>.
Count :- public int Count { get; }
Gets the number of key/value pairs that is present in the SortedList<TKey, TValue>. It is an O(1) operation.
Item[TKey] :- public TValue this[TKey key] { get; set; }
Gets or sets the value associated with the specified key. Getting the value by this property is an o( log n) operation . Setting the value in the SortedList<TKey,TValue> O( log n) operation if key already exist in the SortedList<TKey,TValue>. if key not present in the SortedList<TKey,TValue> setting will be O( n ) operation for unsorted data OR if the new element added at the end of the SortedList<TKey,TValue> this will be an O( log n) operation. if adding a new element require array resizing then this will be an O(n) operation.
Keys :- public System.Collections.Generic.IList<TKey> Keys { get; }
Gets a IList<TKey> containing the keys in the SortedList <TKey, TValue> . it is also an O(1) operation.
Values :- public System.Collections.Generic.IList<TValue> Values { get; }
Gets a IList<TValue> containing the values in the SortedList<TKey, TValue>. it is an O(1) operation.

Creating and adding element in SortedList<TKey, TValue>

1. initialize the SortedList<TKey,TValue> with initial values

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        var sortedList = new SortedList<string,string> {
            {"language","C#"},
            {"topic","SortedList"},
            {"label","Beginner"}
        };
        Console.WriteLine("We are learning "+sortedList["language"]+" "+sortedList["topic"] +" and level : "+sortedList["label"]);
        Console.WriteLine("--------------loop------------");
        foreach (KeyValuePair<string, string> kv in sortedList) {
            Console.WriteLine("K: "+ kv.Key+" V: "+kv.Value);
        }
    }
}

We are learning C# SortedList and level : Beginner
--------------loop------------
K: label V: Beginner
K: language V: C#
K: topic V: SortedList

2. Direct Assign to add new element in SortedList<TKey,TValue>

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        var sortedList = new SortedList<string,string>();
        sortedList["language"]="C#";
        sortedList["topic"]="SortedList";
        sortedList["label"]="Beginner";
        Console.WriteLine("We are learning "+sortedList["language"]+" "+sortedList["topic"] +" and level : "+sortedList["label"]);
        Console.WriteLine("--------------loop------------");
        foreach (KeyValuePair<string, string> kv in sortedList) {
            Console.WriteLine("K: "+ kv.Key+" V: "+kv.Value);
        }
    }
}

We are learning C# SortedList and level : Beginner
--------------loop------------
K: label V: Beginner
K: language V: C#
K: topic V: SortedList

3. Using Add() Method to add new element in SortedList<TKey, TValue>

using System;
using System.Collections.Generic;

class Program
{
    static void Main()
    {
        var sortedList = new SortedList<string,string>();
        sortedList.Add("language","C#");
        sortedList.Add("topic","SortedList");
        sortedList.Add("label","Beginner");
        Console.WriteLine("We are learning "+sortedList["language"]+" "+sortedList["topic"] +" and level : "+sortedList["label"]);
        Console.WriteLine("--------------loop------------");
        foreach (KeyValuePair<string, string> kv in sortedList) {
            Console.WriteLine("K: "+ kv.Key+" V: "+kv.Value);
        }
    }
}

We are learning C# SortedList and level : Beginner
--------------loop------------
K: label V: Beginner
K: language V: C#
K: topic V: SortedList

Previous : C# Collections Next : SortedList<TKey,TValue> Methods in C#