IEnumerable - new instance

To assign IEnumerable to a new instance of IEnumerable, you will need ToList method. Here is an example:

IEnumerable instanceOne;
IEnumerable instanceTwo;

List instanceListOne = new List();

instanceListOne.Add("a");
instanceListOne.Add("b");

instanceOne = instanceListOne;
instanceTwo = instanceOne;

instanceListOne.Add("c");

foreach (string instance in instanceTwo)
{
	Console.WriteLine(instance);
}

Console.WriteLine("Press any key");
Console.ReadKey();

instanceTwo = instanceOne.ToList();
instanceListOne.Add("d");

foreach (string instance in instanceTwo)
{
	Console.WriteLine(instance);
}

Console.WriteLine("Press any key");
Console.ReadKey();

Notice first:

instanceListOne.Add("a");
instanceListOne.Add("b");

instanceOne = instanceListOne;
instanceTwo = instanceOne;

Then:

instanceListOne.Add("c");

I added firs "a" and "b" to instanceListOne, I assigned instanceListOne to instanceOne, and then I assigned instanceOne to instanceTwo, after that I added "c" to instanceListOne, then I went through instanceTwo and result is:

"c" is displayed also in instanceTwo.

Now to have two separate instances of IEnumerable, we need something like:

instanceTwo = instanceOne.ToList();

After that I did something like:

instanceListOne.Add("d");

Result will be still as in previous picture, "d" is not added to instanceTwo, since now we really have separate instances.

Example download from here.