C# | Adding new node or value at the end of LinkedList<T>

Last Updated : 01 Feb, 2019

LinkedList<T>.AddLast Method is used to add a new node or value at the end of the LinkedList<T>. There are 2 methods in the overload list of this method as follows:

AddLast(LinkedList<T>)

AddLast(T)

AddLast(LinkedListNode<T>)

This method is used to add the specified new node at the end of the LinkedList<T>.

Syntax:

public void AddLast (System.Collections.Generic.LinkedListNode<T> node);

Here, node is the new LinkedListNode<T> to add at the end of the LinkedList<T>.

Exceptions:

ArgumentNullException : If the node is null.
InvalidOperationException : If the node belongs to another LinkedList<T>.

Example:

// C# code to add new node 
// at the end of LinkedList 
using System; 
using System.Collections; 
using System.Collections.Generic; 
  
class GFG { 
  
    // Driver code 
    public static void Main() 
    { 
        // Creating a LinkedList of Integers 
        LinkedList<int> myList = new LinkedList<int>(); 
  
        // Adding nodes in LinkedList 
        myList.AddLast(2); 
        myList.AddLast(4); 
        myList.AddLast(6); 
        myList.AddLast(6); 
        myList.AddLast(6); 
        myList.AddLast(8); 
  
        // To get the count of nodes in LinkedList 
        // before removing all the nodes 
        Console.WriteLine("Total nodes in myList are : " + myList.Count); 
  
        // Displaying the nodes in LinkedList 
        foreach(int i in myList) 
        { 
            Console.WriteLine(i); 
        } 
  
        // Adding new node at the end of LinkedList 
        // This will give error as node is null 
        myList.AddLast(null); 
  
        // To get the count of nodes in LinkedList 
        // after removing all the nodes 
        Console.WriteLine("Total nodes in myList are : " + myList.Count); 
  
        // Displaying the nodes in LinkedList 
        foreach(int i in myList) 
        { 
            Console.WriteLine(i); 
        } 
    } 
} 

Runtime Error:

Unhandled Exception:
System.ArgumentNullException: Value cannot be null.
Parameter name: node

Note:

LinkedList<T> accepts null as a valid Value for reference types and allows duplicate values.
If the LinkedList<T> is empty, the new node becomes the First and the Last.
This method is an O(1) operation.

AddLast(T) Method

This method is used to add a new node containing the specified value at the end of the LinkedList<T>.

Syntax:

public System.Collections.Generic.LinkedListNode<T> AddLast (T value);

Here, value is the value to add at the end of the LinkedList<T>.

Return Value: The new LinkedListNode<T> containing value.

Example:

// C# code to add new node containing 
// the specified value at the end 
// of LinkedList 
using System; 
using System.Collections; 
using System.Collections.Generic; 
  
class GFG { 
  
    // Driver code 
    public static void Main() 
    { 
        // Creating a LinkedList of Integers 
        LinkedList<int> myList = new LinkedList<int>(); 
  
        // Adding nodes in LinkedList 
        myList.AddLast(2); 
        myList.AddLast(4); 
        myList.AddLast(6); 
        myList.AddLast(6); 
        myList.AddLast(6); 
        myList.AddLast(8); 
  
        // To get the count of nodes in LinkedList 
        // before removing all the nodes 
        Console.WriteLine("Total nodes in myList are : " + myList.Count); 
  
        // Displaying the nodes in LinkedList 
        foreach(int i in myList) 
        { 
            Console.WriteLine(i); 
        } 
  
        // Adding new node containing the 
        // specified value at the end of LinkedList 
        myList.AddLast(20); 
  
        // To get the count of nodes in LinkedList 
        // after removing all the nodes 
        Console.WriteLine("Total nodes in myList are : " + myList.Count); 
  
        // Displaying the nodes in LinkedList 
        foreach(int i in myList) 
        { 
            Console.WriteLine(i); 
        } 
    } 
} 

Output:

Total nodes in myList are : 6
2
4
6
6
6
8
Total nodes in myList are : 7
2
4
6
6
6
8
20

Note:

LinkedList<T> accepts null as a valid Value for reference types and allows duplicate values.
If the LinkedList<T> is empty, the new node becomes the First and the Last.
This method is an O(1) operation.

Reference: