Scratch parameter passing byref or byval

Question

In scratch I am building a recursive routine that I want to avoid using global variables with. At the moment I am having some issues with parameter passing and need to know whether they are passed to subroutines as ByVal or ByRef and can you change the method?

Answer 1

In Scratch routine variables can't be returned and there is no way to set them to a different value, so that is irrelevant.

The routine block allows you to name an input variable, but not to then use it in a set block, and there's no return block at all.

You can't change it in Scratch, but you can I believe in byob.

Answer 2

There is a way around the problem boisvert is showing in the other anwer. Drag number1 to where 0 is and it will set testvar to number1 for other sprites to use.

You still can't modify the original number1 though.