Using Linq ConvertAll to create a backup of a list before altering the list

Question

I'm working on a project where I have a list of objects with a nested list of which I want to make a backup before I update the original list.

I'm close but I'm having trouble finding the correct syntax so I hope you can help me out here.

This is the original class:

public class TeamClass
{
     public string Country { get; set; }
     public string CountryCode { get; set; }
     public List<double> Points { get; set; }
}

List<TeamClass> originalList = new List<TeamClass>();

Just before I update the points on the OriginalList I want to create a deep copy of the OriginalList so I can "undo" the changes.

Currently I'm using the code below:

 var backupList = Simulation.ConvertAll(x => new TeamClass
 {
     Country = x.Country,
     CountryCode = x.CountryCode,
     Points = new List<double>(x.Points.ConvertAll(p => new double()))
 })
 .OrderByDescending(o => o.Points.Sum())
 .ToList();

Although this code creates a deepcopy of the original list, it replaces all of the points in the list Points by 0 (because of the new double())

However using

Points = x.Points

gives me the correct points but they get updated when the original list gets updated.

I think I have to do something like

Points = new List<double>().AddRange(x.Points)

But I can't find the correct syntax.

Any help is appreciated.

Answer 1

To answer you additional question from comments. It can be done with something like this.

 int N = 4; // Number of desired elements with value
 var backupList = Simulation.ConvertAll(x => new TeamClass
 {
     Country = x.Country,
     CountryCode = x.CountryCode,
     Points = new List<double>(x.Points.Take(N).Concat(x.Points.Skip(N).ToList().ConvertAll(p => new double())));
 })
 .OrderByDescending(o => o.Points.Sum())
 .ToList();

Since double is not nullable datatype, all values after N will be converted to 0.