This post will discuss how to clone a list in C#. The solution should construct a list containing the specified list elements in the same order as the original list.

1. Using List Constructor

To clone a list, we can use a copy constructor, which is a special constructor to initialize a new instance of the List<T> class with a copy of the existing list. Assuming there are no mutable objects in the list, the copy constructor performs a shallow copy.

This method is demonstrated below:

using System;
using System.Collections.Generic;
 
public class Example
{
    public static void Main()
    {
        List<string> source = new List<string>() { "A", "B", "C" };
 
        List<string> clonedList = new List<string>(source);
        Console.WriteLine(String.Join(",", clonedList));
    }
}
 
/*
    Output: A,B,C
*/

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2. Using List<T>.GetRange() (System.Collections.Generic)

We can also use List<T>.GetRange() method that creates a shallow copy of the source List<T> between the specified range.

using System;
using System.Collections.Generic;
 
public static class Extensions
{
    public static List<T> GetClone<T>(this List<T> source) {
        return source.GetRange(0, source.Count);
    }
}
 
public class Example
{
    public static void Main()
    {
        List<string> source = new List<string>() { "A", "B", "C" };
 
        List<string> clonedList = source.GetClone();
        Console.WriteLine(String.Join(",", clonedList));
    }
}
 
/*
    Output: A,B,C
*/

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3. Using Enumerable.ToList() method (System.Linq)

Another approach that creates shallow copy is to call the ToList() on the original list. The following code example demonstrates how ToList() returns a new List<T> containing elements of the original list in the same order.

using System;
using System.Linq;
using System.Collections.Generic;
 
public class Example
{
    public static void Main()
    {
        List<string> source = new List<string>() { "A", "B", "C" };
 
        List<string> clonedList = source.ToList();
        Console.WriteLine(String.Join(",", clonedList));
    }
}
 
/*
    Output: A,B,C
*/

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The following code demonstrates how to call the default Clone() method on each list element. Then ToList() method is called to force immediate query evaluation and return a List<T> containing the query results.

using System;
using System.Collections.Generic;
using System.Linq;
 
public static class Extensions
{
    public static List<string> GetClone(this List<string> source)
    {
        return source.Select(item => (string)item.Clone())
                .ToList();
    }
}
 
public class Example
{
    public static void Main()
    {
        List<string> source = new List<string>() { "A", "B", "C" };
 
        List<string> clonedList = source.GetClone();
        Console.WriteLine(String.Join(",", clonedList));
    }
}
 
/*
    Output: A,B,C
*/

Download  Run Code

That’s all about cloning a List in C#.