From: Grant Hutchins <nertzy@...>
Date: 2007-01-28T20:50:11+09:00
Subject: Re: pass by reference?



On Jan 27, 5:34 am, Wolfgang N�dasi-Donner <won...@donnerweb.de> 
wrote:
>  >>>>> Code >>>>>
>
> def modifying(a_param)
>    a_param = "hi"
> end
>
> def modifying2(a_param=a_value)
>    a_param = "hi"
> end

In these two methods, the = sign is an assignment, which changes the 
memory location of the lvalue to point to the object of the rvalue.

> def modifying3(a_param)
>    a_param[0..-1]= "hi"
> end

This is actually a method call. It could also be written a_param.
[]=(0..-1, "hi") . So the difference is that in this example you are 
actually calling a method on the object that a_param points to. This 
is due to the syntactic sugar Ruby gives to the method named []= which 
in this case is defined on String. See http://www.ruby-doc.org/docs/
ruby-doc-bundle/Manual/man-1.4/syntax.html#assign

So in all three we are passing by value as you define it.