From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2010-11-05T17:43:44+09:00
Subject: Re: the second argument

On Fri, Nov 5, 2010 at 9:10 AM, wroxdb <wroxdb@gmail.com> wrote:
> Hello,
>
> what's the argument of "obj" in:   def []=(index,obj) ?
>
> I don't see it call this method with the second argument.
> Thanks
>
>
> The original code is:
>
> class Array2 < Array
>
>  def [](index)
>    if index>0
>      super(index-1)
>    else
>      raise IndexError
>    end
>  end
>
>  def []=(index,obj)
>    if index>0
>      super(index-1,obj)
>    else
>      raise IndexError
>    end
>  end
>
> end
>
>
> x = Array2.new
>
> x[1]=5

This is syntactic sugar for

x.[]=(1,5)

which is the method you are asking about.

> x[2]=3
> x[0]=1  # Error
> x[-1]=1 # Error

Jesus.