ByVal or ByRef - Arrays

When you declare a variable with an Array data type it can only be passed in using ByRef.
The Array data type is a Value data type.

ByRef

Passing an Array into a subroutine using ByRef allows the original variable to be changed.

ByVal

Passing an Array into a subroutine using ByVal is not possible.
If you try and declare an array parameter that is passed ByVal you will get a compile error

SS - array argument must be byref