From: "David A. Black" <dblack@...>
Date: 2003-12-08T20:16:33+09:00
Subject: Re: Surprising(?) behaviour of the comma operator

Hi --

On Mon, 8 Dec 2003, Frank Schmitt wrote:

> 
> Hi!
> 
> I just stumbled over a (at least for me) surprising behaviour
> of the comma (',') operator:
> 
>   irb(main):001:0> a,b = 1,2
>   [1, 2]
>   irb(main):002:0> puts a.class, b.class
>   Fixnum
>   Fixnum
>   nil
> 
> Ok, no surprises so far. Here we go:
> 
>   irb(main):003:0> a=1, b=2
>   [1, 2]
>   irb(main):004:0> puts a.class, b.class
>   Array
>   Fixnum
>   nil
> 
> that is, a=1, b=2 creates an *Array* a instead of a Fixnum.
> I don't think this is a bug, since others surely have spotted
> this before me, but what's the rationale behind this?

What you've done is essentially:

  a = 1,2

with the side-effect of assigning 2 to b:

  a = 1,b=2


David

-- 
David A. Black
dblack@wobblini.net