Convert IList to array in C#

You're creating an array of Array values. 1 is an int, not an Array. You should have:

IList list = new ArrayList();
list.Add(1);
Array array = new int[list.Count];
list.CopyTo(array, 0);

or, ideally, don't use the non-generic types to start with... use List instead of ArrayList, IList<T> instead of IList etc.

EDIT: Note that the third line could easily be:

Array array = new object[list.Count];

instead.

You can use Cast and ToArray:

Array array = list.Cast<int>().ToArray();

I'm surprised that

 Array array = new Array[list.Count];

even compiles but it does not do what you want it to. Use

 object[] array = new object[list.Count];

And, standard remark: if you can use C#3 or later, avoid ArrayList as much as possible. You'll probably be happier with a List<int>

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