Question

In C# one can instantiate an Array with the special square bracket syntax new int[3]. This is different to other types which you instantiate by calling the constructor new List<int>(). Can you use the ordinary syntax to create an Array?

I tried new System.Array<int>(3) but it blows up

The non-generic type ‘System.Array’ cannot be used with type arguments

Answer 1

System.Array itself is abstract, so you won’t be able to instantiate it using its constructor. And as evidenced by your error, it’s not actually generic either; it only gets its type through implementing generic collection interfaces at runtime (see also this related answer):

Important

In the .NET Framework version 2.0, the Array class implements the System.Collections.Generic.IList<T>, System.Collections.Generic.ICollection<T>, and System.Collections.Generic.IEnumerable<T> generic interfaces. The implementations are provided to arrays at run time, and therefore are not visible to the documentation build tools.

For the above reasons, the System.Array class provides a convenience method called CreateInstance() which you can use instead:

var array = Array.CreateInstance(typeof(int), 3);

Remarks

Unlike most classes, Array provides the CreateInstance method, instead of public constructors, to allow for late bound access.

Be very careful when using this method, though, as the resultant array will not be strongly-typed at compile-time! If you want it to be strongly-typed you must cast it after creating it (and no, simply declaring int[] array won’t be enough):

var array = (int[]) Array.CreateInstance(typeof(int), 3);