C# | Adding the elements of the specified collection to the end of the List Last Updated : 11 Jul, 2025 Comments Improve Suggest changes Like Article Like Report List<T>.AddRange(IEnumerable<T>) Method is used to add the elements of the specified collection to the end of the List<T>. Properties of List: It is different from the arrays. A list can be resized dynamically but arrays cannot. List class can accept null as a valid value for reference types and it also allows duplicate elements. If the Count becomes equals to Capacity, then the capacity of the List increases automatically by reallocating the internal array. The existing elements will be copied to the new array before the addition of the new element. Syntax: public void AddRange (System.Collections.Generic.IEnumerable<T> collection); Parameter: collection: It is the specified collection whose elements will be added to the end of the List<T>. Exception: This method will give ArgumentNullException if the collection is null. Note: The collection itself cannot be null, but it can contain elements that are null if type T is a reference type. The order of the elements in the collection is always preserved in the List<T>. Below programs illustrate the use of above discussed method: Example 1: CSharp // C# program to illustrate the // List.AddRange Method using System; using System.Collections.Generic; class Geeks { // Main Method public static void Main(String[] args) { // Creating a List of Strings List<String> firstlist = new List<String>(); // adding elements in firstlist firstlist.Add("Geeks"); firstlist.Add("GFG"); firstlist.Add("C#"); firstlist.Add("Tutorials"); Console.WriteLine("Before AddRange Method"); Console.WriteLine(); // displaying the item of List foreach(String str in firstlist) { Console.WriteLine(str); } Console.WriteLine("\nAfter AddRange Method\n"); // Here we are using AddRange method // Which adds the elements of firstlist // Collection in firstlist again i.e. // we have copied the whole firstlist // in it firstlist.AddRange(firstlist); // displaying the item of List foreach(String str in firstlist) { Console.WriteLine(str); } } } Output: Before AddRange Method Geeks GFG C# Tutorials After AddRange Method Geeks GFG C# Tutorials Geeks GFG C# Tutorials Example 2: CSharp // C# program to illustrate the // List.AddRange Method using System; using System.Collections.Generic; class Geeks { // Main Method public static void Main(String[] args) { // Creating a List of Strings List<String> firstlist = new List<String>(); // adding elements in firstlist firstlist.Add("Geeks"); firstlist.Add("GFG"); firstlist.Add("C#"); firstlist.Add("Tutorials"); Console.WriteLine("Before AddRange Method"); Console.WriteLine(); // displaying the item of List foreach(String str in firstlist) { Console.WriteLine(str); } Console.WriteLine("\nAfter AddRange Method\n"); // taking array of String string[] str_add = { "Collections", "Generic", "List" }; // here we are adding the elements // of the str_add to the end of // the List<T>. firstlist.AddRange(str_add); // displaying the item of List foreach(String str in firstlist) { Console.WriteLine(str); } } } Output: Before AddRange Method Geeks GFG C# Tutorials After AddRange Method Geeks GFG C# Tutorials Collections Generic List Reference: https://learn.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1.addrange?view=netframework-4.7.2 Create Quiz Comment K Kirti_Mangal Follow 0 Improve K Kirti_Mangal Follow 0 Improve Article Tags : Misc C# CSharp-method CSharp-Generic-List CSharp-Collections-Namespace CSharp-Generic-Namespace +2 More 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