How to remove all nodes of a linked list in C#
The Clear() method
The LinkedList<T> generic class in the System.Collections.Generic namespace provides the Clear() method, which removes all nodes from a linked list in C#.
LinkedList<T>in C# is implemented as a doubly-linked list with insertion and removal as operations.
The figure below illustrates how the Clear() method works:
Syntax
public void Clear ();
Parameters
This function does not take any parameters.
Return value
The Clear() function does not return a value.
Code
Consider the following example code, where we create a linked list of strings and add the names of a few companies to it.
using System;using System.Collections.Generic;class LinkedListClear {static void Main() {string[] companies = {"Google", "Apple", "Microsoft", "Facebook"};LinkedList<string> companyList = new LinkedList<string>(companies);Console.WriteLine("LinkedList Elements - Count : {0}", companyList.Count);Print(companyList);companyList.Clear();Console.WriteLine("LinkedList Elements After Clear() - Count : {0}", companyList.Count);Print(companyList);}private static void Print(LinkedList<string> list) {foreach (var node in list) {Console.Write(node + ", ");}Console.WriteLine("\n");}}
Explanation
-
From line 6 to line 7, we create a linked list that contains four strings -
"Google", "Apple", "Microsoft", "Facebook". -
From line 17 to line 21, we create a helper method,
Print(), to display the linked list nodes. -
In line 12, we call the
Clear()method on the linked list to remove all the nodes from the list. We can see that the list’s count property is zero and no elements are displayed.
Things to note
-
The
Countproperty of the list object is set to zero. -
References to other objects are released, and the
firstandlastpointers are set tonull. -
This is an operation, where
nis the number of elements in the list.
