Clone a List in C#

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#.

1. Using List Constructor

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

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

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

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