On Wed, 15 Mar 2006, Nathan O. wrote:
puts "My name is " + @name
It seems that @name reverts back once I leave the scope of any method
that manipulates it.
As you’ve learned from some of the other responses, @name is an
instance variable. Each instance variable belongs to one object. You
can always tell which object: it’s whatever the default object
(self) is, at the point where the “@var” is executed.
Note that self changes between a class definition and an instance
This code will give you:
In the top level of the class definition, self is the actual class
object (Person), but inside an instance method, it’s the instance
(indicated by the #<Person…> expression).
So… @name in the outer scope is actually an instance variable
belonging to the class object, while inside any instance method, @name
is an instance variable belonging to the instance. The two @name’s
have no connection to each other at all.
You can use class variables to get a variable that can be seen in both
scopes, but if you’ve got a property like “name” and you find yourself
manipulating it outside of any instance method, something’s probably
in need of tweaking in the program design (since the name of any
particular instance shouldn’t be of concern at the class level).
David A. Black (email@example.com)
Ruby Power and Light, LLC (http://www.rubypowerandlight.com)
“Ruby for Rails” chapters now available
from Manning Early Access Program! http://www.manning.com/books/black