Optional function arguments

It's some-what confusing, if you try to over-complicate it.

With optional arguments, they must be at the end of the function's arguments list.

function SomeFunc(a, b, c)
    if a then
        print(tostring(a))
    end
    if b and c then
        print(tostring(b)..tostring(c))
    end
end

SomeFunc("HI!") --> HI!
SomeFunc("Nothing", "Woot") --> Nothing [`c` wasn't specified, so it defaulted to nil, and would be false in the if statement]
SomeFunc("This", "Does", "Work") --> This (new line) DoesWork

What happens is whenever a function is called and not every argument is passed, it sets those arguments that weren't passed to nil.