From: "Mikael Høilund" <mikael@...>
Date: 2008-04-29T20:21:42+09:00
Subject: Re: References in Ruby


On Apr 29, 2008, at 13:02, Marcin Tyman wrote:
> a = 10
> b = a
> a = 50
>
> puts b   # -> puts 10
>
> Why?? Since everything is a reference in Ruby I expected "puts 50".

That's because you're not changing 50, you're changing a. At the third  
line, you're setting a to be a different object than b. Compare to:

 >> a = "Hello"
=> "Hello"
 >> b = a
=> "Hello"
 >> a.upcase!
=> "HELLO"
 >> b
=> "HELLO"

Play around with Object#object_id for a better idea of how this works.