C# | SortedDictionary.Add() Method Last Updated : 11 Jul, 2025 Comments Improve Suggest changes Like Article Like Report This is used to add a specified key and value to the sorted dictionary. The elements are sorted according to TKey. Syntax: public void Add (TKey key, TValue value); Parameters: key: It is the key of the element to add. value: It is the value of the element to add. The value can be null for reference types. Exceptions: ArgumentNullException : If the key is null. ArgumentException : If an element with the same key already exists in the Dictionary. Below are the programs to illustrate the use of Dictionary<TKey, TValue>.Add() Method: Example 1: csharp // C# code to add the specified key // and value into the SortedDictionary using System; using System.Collections.Generic; class GFG { // Driver code public static void Main() { // Create a new SortedDictionary // of strings, with string keys. 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"); // To get count of key/value // pairs in myDict Console.WriteLine("Total key/value pairs in" + " myDict are : " + myDict.Count); // Displaying the key/value // pairs in myDict Console.WriteLine("The key/value pairs" + " in myDict are : "); foreach(KeyValuePair<string, string> kvp in myDict) { Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value); } } } Output: Total key/value pairs in myDict are : 6 The key/value pairs in myDict are : 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 Example 2: csharp // C# code to add the specified key // and value into the SortedDictionary using System; using System.Collections.Generic; class GFG { // Driver code public static void Main() { // Create a new SortedDictionary // of strings, with string keys. 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"); // The Add method throws an // exception if the new key is // already in the dictionary. try { myDict.Add("Russia", "Moscow"); } catch (ArgumentException) { Console.WriteLine("An element with Key " + "= \"Russia\" already exists."); } } } Output: An element with Key = "Russia" already exists. Note: A key cannot be null, but a value can be. If the value type TValue is a reference type. This method is an O(log n) operation, where n is Count of elements in the SortedDictionary. Reference: https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.sorteddictionary-2.add?view=netframework-4.7.2 Create Quiz Comment R rupesh_rao Follow 0 Improve R rupesh_rao Follow 0 Improve Article Tags : C# CSharp-method CSharp-Generic-Namespace CSharp SortedDictionary Class Explore IntroductionC# Tutorial 2 min read Introduction to .NET Framework 6 min read C# .NET Framework (Basic Architecture and Component Stack) 6 min read C# Hello World 2 min read Common Language Runtime (CLR) in C# 4 min read FundamentalsC# Identifiers 2 min read Data Types in C# 6 min read C# Variables 4 min read C# Literals 5 min read Operators in C# 7 min read C# Keywords 5 min read Control StatementsC# Decision Making (if, if-else, if-else-if ladder, nested if, switch, nested switch) 5 min read C# Switch Statement 4 min read Loops in C# 4 min read C# Jump Statements (Break, Continue, Goto, Return and Throw) 4 min read OOP ConceptsClass and Objects in C# 4 min read Constructors in C# 5 min read C# Inheritance 3 min read Encapsulation in C# 2 min read C# Abstraction 4 min read MethodsMethods in C# 4 min read Method Overloading in C# 4 min read Method Parameters in C# 4 min read Method Overriding in C# 7 min read Anonymous Method in C# 2 min read ArraysArrays in C# 6 min read Jagged Arrays in C# 4 min read Array Class in C# 5 min read How to Sort an Array in C# | Array.Sort() Method Set - 1 8 min read How to find the rank of an array in C# 2 min read ArrayListArrayList in C# 6 min read ArrayList Class in C# 4 min read C# | Array vs ArrayList 2 min read StringStrings in C# 6 min read C# Verbatim String Literal - @ 5 min read C# String Class 9 min read C# StringBuilder 2 min read C# String vs StringBuilder 3 min read TupleC# Tuple 7 min read C# Tuple Class 3 min read C# ValueTuple 7 min read C# ValueTuple Struct 4 min read IndexersC# Indexers 5 min read C# Multidimensional Indexers 5 min read C# - Overloading of Indexers 3 min read Like