Sharing variables between different files in a plugin

Question

Supposing I have two scripts that share variables. What is the preferred way to do this, supposing I wanted to keep the variables only in one place? Is there a way to keep them script-local and not global?

---

Context: I'm writing two syntastic syntax checkers that both the same errorformat (because underneath they use the same compiler). What would be the preferred way to share an errorformat variable between the two files of these syntax checkers?

I was later explained by the maintainer that since these variables aren't meant to be changed often, I should just have them in two places. This question is still here because the how-to question is still answerable, although it is no longer relevant in the original context.

Answer 1

You should use a global variable:

:h global-variable

                    *global-variable* *g:var* *g:*
Inside functions global variables are accessed with "g:".  Omitting this will
access a variable local to a function.  But "g:" can also be used in any other
place if you like.

You can use it as follow:

let g:my_variable = 1

And then g:my_variable is accessible from anywhere within vim and plugins.