From: Gennady <gfb@...>
Date: 2003-03-25T04:43:12+09:00
Subject: Re: [puts] - bug or feature?


----- Original Message -----
From: "Meinrad Recheis" <meinrad.recheis@aon.at>
Newsgroups: comp.lang.ruby
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Monday, March 24, 2003 11:19 AM
Subject: [puts] - bug or feature?


> hi ruby community,
>
> i wrote a ruby script and executed it, here are the lines and the results:
> puts 3.to_s + 'b'      # => 3b

[1] equivalent to: (puts(3.to_s + 'b'))
puts prints out expression 3.to_s + 'b' converted to String, that is '3b'.

> puts (3).to_s + 'b'    # => 3

[2] equivalent to: (puts(3)).to_s + 'b')
puts prints out expression 3 converted to String, that is '3'. Then
expression nil.to_s + 'b' is being evaluated (nil is the return value of
puts). There's neither variable assignment nor another puts for the last
evaluation, so it is just discarded.


> puts ((3).to_s + 'b')  # => 3b

[3] Same as [1]
>
> i am confused about that.
> i tried that in irb also and i got
>
> (3).to_s + 'b'
> => "3b"

By default irb prints out the result of an input expression with 'p', so
this is roughly equivalent to explicit expression
p ((3).to_s + 'b')

This looks like case [3] doesn't it ;-)

>
> but
>
> puts (3).to_s + 'b'
> 3
> => "b"

And this looks like case [2] plus previously discarded value 'b' is printed
out with 'p' (again, default irb behaviour).


>
> cheers
> - meinrad
>
>
>