Copy one type of List<> into another type of List<>

Question

For some reason, i need to copy only view details from one list into another list.

public class c1
{
public string id{get;set;}
public string firstname{get;set;}
public string lastname{get;set;}
public string category{get;set;}
public string gender{get;set;}
}

public class c2
{
public string id{get;set;}
public string firstname{get;set;}
}

Here, in runtime, I will get all the details for the c1 class, and I need to store only 2parameters to store into c2. How can i achieve this? I tried below, but its not working!!

dynamic d=from a in c1 
      select new   
      {
       a.id,
       a.firstname
      };

List<c2> c2list=d;

Answer 1

Use ToList method https://docs.microsoft.com/en-us/dotnet/api/system.linq.enumerable.tolist?view=net-6.0

List<c2> list2 = (from a in c1 
                  select new c2  
                  {
                      a.id,
                      a.firstname
                  }).ToList();

Answer 2

Here is a basic example:

void Main()
{
    List<c1> c1List = new List<c1>();
    List<c2> c2List = new List<c2>();
    
    c1 example1 = new c1 {
        category = "some category",
        firstname = "John",
        gender = "some gender",
        id = "1",
        lastname = "Smith",
    };
    
    c1List.Add(example1);

    c2List.AddRange(c1List.Select(x => new c2 {
        firstname = x.firstname,
        id = x.id
    }));
    

    
}

// You can define other methods, fields, classes and namespaces here

public class c1
{
    public string id { get; set; }
    public string firstname { get; set; }
    public string lastname { get; set; }
    public string category { get; set; }
    public string gender { get; set; }
}

public class c2
{
    public string id { get; set; }
    public string firstname { get; set; }
}

This outputs them into a list as follows: