C# | Removing all the elements from the List

01 Feb, 2019
List class represents the list of objects which can be accessed by index. It comes under the System.Collection.Generic namespace. List class can be used to create a collection of different types like integers, strings etc. List class also provides the methods to search, sort, and manipulate lists. List.Clear Method is used remove the all the elements from the List.
Properties:
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 increased 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 Clear ();
Below programs illustrate how to remove all the elements from the List:
Example 1:
// C# program to remove all the// elements from a Listusing System;using System.Collections.Generic;  class Geeks {      // Main Method    public static void Main()    {          // Creating a List of integers        List<int> list1 = new List<int>();          // Inserting the elements into the List        list1.Add(1);        list1.Add(4);        list1.Add(3);        list1.Add(1);        list1.Add(2);          // Displaying the count of elements        // contained in the List before        // removing all the elements        Console.Write("Number of elements in the List Before Removing: ");          // using Count property        Console.WriteLine(list1.Count);          // Removing all elements from list        list1.Clear();          // Displaying the count of elements        // contained in the List after        // removing all the elements        Console.Write("Number of elements in the List After Removing: ");          // using Count property        Console.WriteLine(list1.Count);    }}
Output:
Number of elements in the List Before Removing: 5
Number of elements in the List After Removing: 0

Example 2:
// C# program to remove all the// elements from a Listusing System;using System.Collections.Generic;  class Geeks {      // Main Method    public static void Main()    {          // Creating a List of strings        List<string> list1 = new List<string>();          // Inserting the elements into the List        list1.Add("Welcome");        list1.Add("To");        list1.Add("Geeks");        list1.Add("for");        list1.Add("Geeks");        list1.Add("Geeks");        list1.Add("Geeks");          // Displaying the count of elements        // contained in the List before        // removing all the elements        Console.Write("Number of elements in the List Before Removing: ");          // using Count property        Console.WriteLine(list1.Count);          // Removing all elements from list        list1.Clear();          // Displaying the count of elements        // contained in the List after        // removing all the elements        Console.Write("Number of elements in the List After Removing: ");          // using Count property        Console.WriteLine(list1.Count);    }}
Output:
Number of elements in the List Before Removing: 7
Number of elements in the List After Removing: 0

Reference:
https://docs.microsoft.com/en-us/dotnet/api/system.collections.generic.list-1.clear?view=netframework-4.7.2
CSharp-Collections-Namespace
CSharp-Generic-List
CSharp-Generic-Namespace
CSharp-method
C#
Writing code in comment?
Please use ide.geeksforgeeks.org,
generate link and share the link here.
C# Dictionary with examples
Introduction to .NET Framework
C# | Delegates
C# | Multiple inheritance using interfaces
Differences Between .NET Core and .NET Framework
C# | Method Overriding
C# | Data Types
C# | Constructors
C# | Class and Object
Extension Method in C#