From: "Hal E. Fulton" <hal9000@...>
Date: 2000-11-30T21:50:53+09:00
Subject: [ruby-talk:6672] Re: printing/accessing arrays and hashes

----- Original Message ----- 
From: Dave Thomas <Dave@thomases.com>
To: ruby-talk ML <ruby-talk@netlab.co.jp>
Sent: Wednesday, November 29, 2000 9:41 PM
Subject: [ruby-talk:6665] Re: printing/accessing arrays and hashes


> raja@cs.indiana.edu (Raja S.) writes:
> 
> > Interesting that Ruby does a #to_s on the elements of the array
> > first.
> 
> Actually, what happens is that when you concatenate something to an
> existing string, if that something isn't already a string, its to_str
> method is called.
> 
>    "a" + 1
>    -:1:in `+': failed to convert Fixnum into String (TypeError)
>   from -:1
> 
>    class Fixnum
>       def to_str
>         "Number: " + to_s
>       end
>    end
> 
>    "a" + 1     #=> "aNumber: 1"
> 

That's interesting, Dave. Is the behavior of << the same? Because I 
have found that the docs say "anObject" but it only seems to work
with another string.

Why, incidentally, is to_str called instead of to_s? I have never
understood that yet. Same for to_a and to_ary.

Hal