Convert C# Type to the type of an array of type

Question

I need the Type of an Array of n elements of a type given in a Type variable. I'm getting round the problem like this:

Type foo;
int n;

Type newType=(Array.CreateInstance(foo,n)).GetType();

This works but it does mean I'm actually creating an unused array just to get it's type. I'm sure there must be a better way!

Answer 1

You can use Type.MakeArrayType() :

Type foo = typeof(Foo);
Type arrayType = foo.MakeArrayType();

This returns the Type of an one-dimensional array of Foo . The length of the array is not relevant for the type.

For multi-dimensional arrays you can use this overload

Type foo = typeof(Foo);
int dimensions = 5;
Type arrayType = foo.MakeArrayType(dimensions);