How do I copy items from list to list without foreach?

Question

How do I transfer the items contained in one List to another in C# without using foreach?

Answer 1

You could try this:

List<Int32> copy = new List<Int32>(original);

or if you're using C# 3 and .NET 3.5, with Linq, you can do this:

List<Int32> copy = original.ToList();

---

I see that this answer is still getting upvotes. Well, here's a secret for ya: the above answer is still using a foreach. Please don't upvote this any further.

Answer 2

To add the contents of one list to another list which already exists, you can use:

targetList.AddRange(sourceList);

If you're just wanting to create a new copy of the list, see Lasse's answer.

Answer 3

For a list of elements

List<string> lstTest = new List<string>();

lstTest.Add("test1");
lstTest.Add("test2");
lstTest.Add("test3");
lstTest.Add("test4");
lstTest.Add("test5");
lstTest.Add("test6");

If you want to copy all the elements

List<string> lstNew = new List<string>();
lstNew.AddRange(lstTest);

If you want to copy the first 3 elements

List<string> lstNew = lstTest.GetRange(0, 3);

Answer 4

And this is if copying a single property to another list is needed:

targetList.AddRange(sourceList.Select(i => i.NeededProperty));

Answer 5

This method will create a copy of your list but your type should be serializable.

Use:

List<Student> lstStudent = db.Students.Where(s => s.DOB < DateTime.Now).ToList().CopyList(); 

Method:

public static List<T> CopyList<T>(this List<T> lst)
    {
        List<T> lstCopy = new List<T>();
        foreach (var item in lst)
        {
            using (MemoryStream stream = new MemoryStream())
            {
                BinaryFormatter formatter = new BinaryFormatter();
                formatter.Serialize(stream, item);
                stream.Position = 0;
                lstCopy.Add((T)formatter.Deserialize(stream));
            }
        }
        return lstCopy;
    }

Answer 6

Easy to map different set of list by linq without for loop

var List1= new List<Entities1>();

var List2= new List<Entities2>();

var List2 = List1.Select(p => new Entities2
        {
            EntityCode = p.EntityCode,
            EntityId = p.EntityId,
            EntityName = p.EntityName
        }).ToList();

Answer 7

OK this is working well From the suggestions above GetRange( ) does not work for me with a list as an argument...so sweetening things up a bit from posts above: ( thanks everyone :)

/*  Where __strBuf is a string list used as a dumping ground for data  */
public List < string > pullStrLst( )
{
    List < string > lst;

    lst = __strBuf.GetRange( 0, __strBuf.Count );     

    __strBuf.Clear( );

    return( lst );
}

Answer 8

public static List<string> GetClone(this List<string> source)
{
    return source.Select(item => (string)item.Clone()).ToList();
}

Answer 9

Here another method but it is little worse compare to other.

List<int> i=original.Take(original.count).ToList();