From: Jamal Soueidan <jkhaledsoueidan@...>
Date: 2007-04-04T21:43:14+09:00
Subject: Re: Everything is a object?

Eleanor McHugh wrote:
> On 4 Apr 2007, at 11:02, Jamal Soueidan wrote:
>> I have been reading about these various boolean returns, how Ruby look
>> at them, as you mentioned false and nil is the only objects which are
>> considered false.
>>
>> But I thought you did not need to define/declare any variables before
>> using it, but this has been misunderstood, you should somehow  
>> assign the
>> variable to something before trying to use it, since Ruby "Still"  
>> don't
>> know what object it is, right?
> 
> The point is that you don't have to define a variable before you make
> an assignment to it, much like in older variants of BASIC. Assignment
> implicitly declares the variable to exist within the specified scope.
> However until you make an assignment the interpreter is not aware of
> the variable's existence (because logically it does not yet exist)
> and so attempts to reference it will fail to produce a reference to
> an object. An attempt will also be made to apply the token to the
> current object as a method, and if this too fails then the
> interpreter has no choice but to flag an error condition because
> semantically your program is broken - it makes no sense.

:D

So until I assign something to it, the interpreter would know nothing 
about what object it is.

In C# you can declare every variable what type it is like this:
String mystring;

I assume I could do that in Ruby also:
@var = String.new

But no need since Ruby would take care of this automatic when you assign 
something to variables.

When I write attributes in my code:
attr_assoccer :var

I assume > then < the interpreter knows only that @var is a object (base 
class)?

So before I can use @var.

- I can either declare it, so the interpreter knows something about it 
(base class object)
 OR
- I can assign something to it, so the interpreter knows what type it is

@var = 'string'

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