Linked List in C#

In this article, we will learn about the LinkedList class.

C# LinkedList class uses the concept of doubly linked list. The LinkedList Collection represents a doubly linked list. It allows insertion, deletion and other operations from the linked list. This collection is found in System.Collections.Generic namespace.

Creating a LinkedList

We create a linked list in C# using the following syntax:
LinkedList<T> l1 = new LinkedList<T>();
<T> here denotes any datatype of which we want to create a linked list of.

Properties of Linked List

• Count: This property gets the number of nodes actually contained in the LinkedList.</li>
• First: This property gets the first node of the LinkedList.</li>
• Last: This property gets the last node of the LinkedList.</li> </ul>

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  Methods of Linked List

  • AddFirst(T): This method adds a new node containing the specified value at the start of the LinkedList.</li>
  • AddLast(T): This method adds a new node containing the specified value at the end of the LinkedList.</li>
  • Contains(T): This method determines whether a value is in the LinkedList.</li>
  • Remove(T): This method removes the first occurrence of the specified value from the LinkedList.</li>
  • RemoveFirst(): This method removes the node at the start of the LinkedList.</li>
  • RemoveLast(): This method removes the node at the end of the LinkedList.</li>
  • Clear(): This method removes all the nodes from the LinkedList.</li> </ul>

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    LinkedList Operation Examples:

    Different LinkedList operations are demonstrated in the example below:

    using System;
    using System.Collections.Generic;
    namespace LinkedListDemo {
        class Example {
            static void Main(string[] args) {
                LinkedList < int > L = new LinkedList < int > ();
                L.AddFirst(5);          // Adds to the beginning
                L.AddFirst(2);          
                L.AddLast(4);           // Adds to the ending
                L.AddLast(9);
                foreach(int i in L) {
                    Console.Write(i + " ");
                }
                Console.WriteLine();
                L.RemoveFirst();        // Removes from the beginning
                L.RemoveLast();         // Removes from the ending
                foreach(int i in L) {
                    Console.Write(i + " ");
                }
                Console.WriteLine();
                Console.WriteLine(list.Contains(3));    // Checks if 3 is present in the list
                Console.WriteLine(list.Contains(5));    // Checks if 5 is present in the list
                Console.WriteLine(list.First.Value);    // 'First' returns the first node in list
                                                        // 'Value' returns the value of the node
            }
        }
    }
    

    Output:

    2 5 4 9
5 4
False
True
5
    

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    Task

    In the editor below, perform the different tasks as directed.