If an array is used as an element in struct (C#) , where is it stored?

Question

We use struct in C# whenever possible mainly because it is stored on the stack and no objects are created for it. This boosts the performance.

On the other hand, arrays are stored on the heap.

My question is, if I include an array as an element of the struct, something as follows:

struct MotionVector
{
    int[] a;
    int b;
}

Then what will be the consequences. Will that array be stored on stack? Or the performance advantage of using struct will be lost?

Answer 1

Only the pointer to the array will be stored in the stack. The actual array will be stored in the heap.

Answer 2

int[] a is a reference type i.e. it references an array of integers. The 'reference' itself will be stored on the stack. However, the data it references will be stored on the heap when you do something like this:

MotionVector z;
z.a = new int[10];