fixed statement for a single array element

Question

Is the following code correct inside a method?

int[] a = { 1, 2, 3, 4, 5 };
unsafe
{
    fixed (int* p = &a[0])
    {
        p[1] = 3;
    }
}

It has no errors but since a[0] is fixed and a[1] is not fixed explicitly, there may be some GC memory move for a[1].

How about this one?:

int[] a = { 1, 2, 3, 4, 5 };
unsafe
{
    fixed (int* p = &a[1])
    {
        p[0] = 3;
    }
}

Answer 1

Both the following assigns the address of the first element in array arr to pointer p.

fixed (double* p = arr) 

is the same as

fixed (double* p = &arr[0])

in your case you assign the second element to a pointer

fixed (double* p = &arr[1])

In any case the array is pinned and protected from moving.