I'll elaborate

sub fudge($){ print @_ }
[download]

that is a function declaration -- it doesn't print anything

fudge(1);
fudge 2;
[download]

those are function calls, it prints 1 then prints 2

If you wrote

fudge 1,2;
[download]

the prototype ($) ensures fudge only gets 1 argument

If you try to force the issue with

fudge(1,2);
[download]

You'll get an error

$ perl  -le " sub fudge($){print @_}  fudge(1,2);
Too many arguments for main::fudge at -e line 1, near "2)"
Execution of -e aborted due to compilation errors.
[download]

Next time, when you get links, follow them, read them, its what we all do :)