From: James Edward Gray II <james@...>
Date: 2006-03-08T22:50:36+09:00
Subject: Re: newbie question about scope, variables, declarations of variables and option strict (as in perl)

On Mar 8, 2006, at 3:01 AM, Talha Oktay wrote:

> When I qualify log with $ as
> $log, it becomes global and I no longer receive error. I have tried it
> qualifying with @ etc. but the received the same error.

No, this works too (after you fix your Logger constructor call):

require 'logger'

@log = Logger.new("test.log")  #some other logger settings are ignored.

def func
   @log.debug "a statement" # error is reported here when func is  
called below
   # some code
end

#some code continues
func


> What I am asking is, what is scope of log?

It's a local variable, scoped to the file it is defined in.  It would  
not be available inside class, module, or method definitions though,  
because they are not closures.

> What kind of variable is it?

Local.

> It is the local or instance variable of what, Object?

To the file.

> But what about log?  How  can  I  access it in a function without  
> making it global?

You could pass it as a parameter, or make it an instance variable, as  
shown above.

> Is there a way to make variables local to a file as perl does with  
> "my".

This is how it functions.

> Is there a strict option that prevents unintended variable creation  
> because
> of typos. Is there a way force predeclaration of variables?

You must assign to a local before you can use it in Ruby.  That's why  
you got the error.  ;)

James Edward Gray II